Chelating-agent-free incorporation of isolated Ni single-atoms within BEA Zeolite for enhanced biomass hydrogenation

Chelating-agent-free incorporation of isolated Ni single-atoms within BEA Zeolite for enhanced biomass hydrogenation | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Chelating-agent-free incorporation of isolated Ni single-atoms within BEA Zeolite for enhanced biomass hydrogenation Wenhao Luo, Meng Liu, Caixia Miao, Yumeng Fo, Wenxuan Wang, Yao Ning, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5796369/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Precisely tailoring metal single-atoms within zeolite scattfolds and understanding the origin of the unique behavior of such atomically dispersed catalysts are pivotal and challenge in chemistry and catalysis. Herein, we have successfully fabricated Ni single-atoms within BEA zeolite (Ni 1 @Beta) through a facile in situ two-step hydrothermal strategy, notably without using any chelating agent for stabilizing Ni species. With the aid of advanced characterization techniques, such as aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM), X-ray absorption spectroscopy (XAS), etc, and combined with density functional theory (DFT) calculations, the nature and micro-environment of isolated Ni species, which are incorporated within 6-membered rings and stabilized by four skeletal oxygens of Beta zeolite, have been identified. The as-obtained Ni 1 @Beta exhibits a superior performance in terms of activity (with a turnover frequency (TOF) value up to 114.1 h -1 ) and stability (for 5 consecutive runs) in the selective hydrogenation of furfural, surpassing those of Ni nanoparticle analogues and previously reported Ni-based heterogeneous catalysts. This study provides an efficient strategy for the fabrication of non-noble metal single-atoms within zeolites, which could be of great help for the design of metal-zeolite combinations in the chemoselective reactions involved in biomass conversion and beyond. Physical sciences/Chemistry/Catalysis/Catalyst synthesis Physical sciences/Chemistry/Catalysis/Heterogeneous catalysis Physical sciences/Chemistry/Green chemistry/Renewable energy Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Zeolites, with ordered microporous architectures, tunable functions and high specific surface area as well as excellent thermal stability, render them the catalytic workhorses of various reactions in chemical industries and refineries. 1,2 Additionally, zeolites have been shown to be versatile and powerful scaffolds for incorporating small metal entities in terms of nanoclusters or even isolated atoms, to generate efficient bifunctional catalysts. 3-5 Single-atom catalysts (SACs) have emerged as a new frontier in catalysis science and have attracted extensive attention because of the maximum atom efficiency and unique catalytic properties. 6-8 Zeolite incorporated metal single-atoms are the suitable candidates for high-activity catalysis, which not only capitalize on the advantages of ingenious atomic utilization and the resulting unique performance but also achieve an outstanding stability against sintering or leaching by the confinement effect of zeolites. 9-11 Common methods for incorporating metal single-atoms within zeolites involve post-synthesis approaches (such as impregnation, ion exchange) or in situ synthesis methods. Although atomically dispersed metal atoms can be introduced into zeolites by post-synthesis treatments, only low metal loading contents can be achieved (<0.2 wt %). 12-14 Moreover, due to the weak interaction between metal atoms and the zeolite framework, these isolated metal atoms could migrate to the surface and sinter into large particles during thermal treatment or under reaction conditions. 15 To this end, in situ metal incorporation during the zeolite synthesis process is preferable and has more recently been employed for anchoring isolated atoms into zeolites. 16,17 Generally, such incorporation approaches are implemented by using a suitable chelating agent to inhibit metal precipitation or agglomeration during the zeolite synthesis. For example, Yu et al. reported an in situ hydrothermal method for incorporating isolated Rh metal atoms inside pure-silica MFI zeolite by using ethylenediamine as a chelating ligand. 16 Similarly, Li et al. also incorporated isolated Pt cations into Y zeolite through an in situ hydrothermal synthesis method, in which H 2 PtCl 6 was stabilized by 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane (TAPTS). 17 Obviously, these reported hydrothermal synthesis strategies for incorporating metal single-atoms within zeolites rely heavily on the usage of a suitable ligand that can coordinate with metal ion to avoid metal precipitation or hydrolysis during the synthetic process. However, the addition of chelating agents generally interrupts the assembly of a zeolite building units during crystallization process, and the strategy is limited within only a small number of zeolite synthesis systems. Additionally, most successful encapsulation is realized on noble metals with a high melting point (i.e., Pt and Rh), while non-noble metals are rarely reported because of their increased susceptibility to metal migration and agglomeration during the calcination and reduction process. Therefore, it is highly desirable to develop a facile, applicable synthesis method to incorporate non-noble metal single-atoms within zeolites. In this work, we report a simple and efficient in situ two-step hydrothermal synthesis method to directly incorporate Ni single-atoms into the micropores of zeolite Beta without using chelating agent for stabilizing metal precursors. The proposed in situ two-step hydrothermal method firstly generates crystal nuclei in nucleation process at a relatively low temperature, and then adds metal precursor to continue crystallization at high temperature.The nature of Ni single-atoms was confirmed by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM), X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy of CO adsorbed (FT-IR-CO). The density functional theory (DFT) calculations show that Ni single-atoms locate in 6-member ring (6-MR) of BEA zeolite and are stabilized by zeolite skeletal oxygens. Benefiting from the unique coordination environment of incorporated single Ni cations, the as-synthesized Ni 1 @Beta catalyst exhibits remarkable performance in the selective hydrogenation of biomass-derived furfural (FF) to furfuryl alcohol (FAL). This efficient synthesis approach for metal single-atoms incorporated within zeolite-based materials may open new perspectives for the rational design of catalysts for chemoselective reactions in biomass valorization and beyond. Results Synthetic approach for incorporation of Ni single atoms. Scheme 1 illustrates the in situ incorporation approach for the synthesis of the atomically dispersed Ni incorporated within Beta zeolite, namely Ni 1 @Beta. The metal incorporation is implemented by a two-step process, including the nucleation step of the alumino-silicate gel with a molar composition of SiO 2 /Al 2 O 3 /TEAOH/H 2 O/Na 2 O = 1/0.014/0.19/7.21/0.042 at 100°C, and a subsequent zeolite crystallization with the introduction of nickel nitrate as the metal precursor at 140°C. The as-obtained zeolites were then washed, dried, calcinated and reduced to generate the target Ni 1 @Beta. For comparison, Ni/Beta was also prepared via wet impregnation of Beta with Ni(NO 3 ) 2 solution. Notably, Ni 1 @Beta shows a colour of white even after a reduction at 500°C, which is quite different from the dark colour of Ni/Beta (Supplementary Fig. 1), reflecting the unique configuration of Ni species in Ni 1 @Beta. The first step of the nucleation process is essential for the successful incorporation of Ni single-atoms within Beta zeolite. When in situ one-step hydrothermal approach is applied for incorporating Ni metal into Beta zeolite, the high pH (> 12) favoring nucleation and crystallization of BEA zeolite could result in a rapid metal precipitation and further lead to a failure of metal incorporation (Supplementary Fig. 2a, 3). Iglesia et al. also confirmed many cationic precursors (e.g., Ru, Pt and Ag) precipitate as massive hydroxides in the alkaline media required for zeolite synthesis, resulting in the early formation of colloidal particles too large for encapsulation. 18 It is widely accepted that the direct incorporation of metal atoms during in situ hydrothermal synthesis needs an addition of a chelating agent into the formula for avoiding the agglomeration of the metal precursor in a basic solution. The protocol has enabled the successful incorporation of Pt, Pd and Rh, Ir, Re, and Ag clusters within LTA, as well as Pt, Pd, Ru, and Rh clusters within GIS and SOD. 19 , 20 Notably, in the proposed in situ two-step hydrothermal method, chelating agent was not used to stabilize Ni metal species, and the separating preliminary nucleation step can effectively avoid the formation of bulk Ni metal hydroxides and prevent the negative impact of the metal precursor on the zeolite self-assembly under the hydrothermal process (Supplementary Fig. 2, 3). Characterization and validation of incorporation of isolated Ni single-atoms within BEA Zeolite. X-ray diffraction (XRD) spectroscopy was employed to determine the crystalline structure of synthesized Ni-containing zeolites. As shown in Supplementary Fig. 4, the diffraction peaks of Ni 1 @Beta and Ni/Beta match well with the BEA zeolite (JCPDS no.: 47–0183). Taking the crystallinity of synthesized Beta zeolite as 100%, the calculated crystallinity of Ni 1 @Beta decreases a little to 95% (Supplementary Table 1), indicating that the incorporation of nickel metal precursors did not interfere with the crystallization process. Importantly, no diffraction peaks corresponding to Ni or NiO are detected, demonstrating the high dispersion of Ni species in the as-synthesized zeolite samples. In addition, the Ni 1 @Beta exhibits a standard type I isotherm with a Brunauer-Emmett-Teller (BET) surface area of about 697 m 2 /g, indicating a microporous crystal structure (Supplementary Fig. 5, 6 and Supplementary Table 2). The Ni content of Ni 1 @Beta and Ni/Beta is determined to be ~ 1.1 wt % by inductively coupled plasma-optical emission spectroscopy (ICP-OES) (Supplementary Table 1). Aberration-corrected scanning transmission electron microscopy (AC-STEM) and the corresponding energy-dispersive X-ray (EDX) spectral mapping were further employed to study the metal dispersion in Ni 1 @Beta and Ni/Beta. No Ni particles can be visible for the Ni 1 @Beta by AC-STEM in the bright-field images, reflecting the good dispersion of Ni species (Fig. 1 a, 1 b). Clearly, as displayed in Fig. 1 c, a lattice fringe spacing of ~ 1.13 nm corresponds to hkl (101) plane of Beta zeolite is observed in the high magnification STEM image of Ni 1 @Beta, again in line with the XRD results that the crystallinity of Beta zeolite is limitedly influenced by the Ni incorporation. High-angle annular dark-field (HAADF) STEM image of Ni 1 @Beta and elemental mappings further confirm the uniform distribution of Ni species through the whole Beta zeolite (Fig. 1 d). To gain the atomic resolution, AC-HAADF-STEM has been applied for Ni 1 @Beta, and atomically dispersed Ni species are clearly visualized as isolated bright dots in the AC-HAADF-STEM images (Fig. 1 e, 1 f, highlighted by white circle). In contrast, Ni/Beta prepared via the conventional wet impregnation method shows an average Ni particle size of ~ 7.6 nm, together with some large Ni nanoparticles observed on the surface of the Beta zeolite (Supplementary Fig. 7). The results of temperature-programmed desorption of hydrogen (H 2 -TPD) also confirm that the average size of Ni particles on Ni 1 @Beta are much smaller than that of Ni/Beta (Supplementary Fig. 8). X-ray absorption spectroscopy (XAS) was further employed to provide the chemical states and local coordination information of Ni species. Figure 2 a and 2 b show the X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra of Ni 1 @Beta and Ni/Beta, and those of Ni foil and NiO as references. The detailed structural parameters obtained from EXAFS fittings are presented in Supplementary Table 2. As shown in Fig. 2 a, both Ni 1 @Beta and NiO share a comparable Ni valence state of + 2, and Ni/Beta shows a slightly lower valence state of Ni between 0 and + 2. In contrast, the XANES spectrum of Ni/Beta is much similar to Ni foil, but the white line intensity is higher, indicating that Ni species possess a higher valence state than the Ni foil due to the presence of small Ni particles, 16 , 21 , 22 which is consistent with the results of XPS. The first pre-edge peak at 8333 eV could be attributed to the 1s→3d electronic transition of Ni cations in an octahedral symmetry, 23 which is normally forbidden due to orbital symmetry mismatch. 24 Only slight (p-d) orbital mixing in distorted local symmetry can provide some probability for the 1s→3d transitions. Additionally, the second pre-edge peak at 8339 eV is attributed to the 1s→4p z electronic transition, which often corresponds to the fingerprint of a square-planar Ni-O 4 structure. 25 The pre-edge peaks of Ni 1 @Beta show markedly weakened intensity both at 8333 and 8339 eV, indicating a significant distorted Ni-O 4 geometry, rather than a square-planar structure. Combined with theoretical calculation, we propose a structure of Ni single atoms locate in a distorted tetrahedral coordination geometry. In the EXAFS spectrum of Ni 1 @Beta, significant peaks are detected at 1.63 and 2.76 Å (without phase correction), which could be identified as first shell Ni-O and second shell Ni-O-Si(Al) scattering paths, respectively (Fig. 2 b). No obvious Ni-Ni peak and Ni-O-Ni peak can be visualized in Ni 1 @Beta, demonstrating that the Ni species exist as isolated single atoms. According to EXAFS fitting results (Supplementary Fig. 9, 10) and quantitative structure parameters (Supplementary Table 3), Ni-O coordination number (CN) is ~ 4.0, indicating the isolated Ni species stabilized by four oxygen atoms in Beta zeolite framework. This model also matches well to the theoretically predicted structure that the Ni atom is coordinated with four O atoms, forming a distorted quasi-planar Ni-O 4 structure (Fig. 2 d). For Ni/Beta, based on the EXAFS fitting results, the peaks at 2.03 Å with a CN of ~ 2.1 and at 2.50 Å with a CN of ~ 7.3 corresponding to Ni-O and Ni-Ni metallic, respectively. It indicates that some large Ni nanoparticles are formed on the Ni/Beta, which is in accordance with the observation of TEM measurements. In addition, the wavelet-transformed (WT) EXAFS counter plots of Ni 1 @Beta directly show the absence of Ni-Ni metallic bonds (Supplementary Fig. 11). Together, all the above results demonstrate that the Ni species in Ni 1 @Beta are atomically distributed and stabilized by four oxygen atoms in Beta zeolite framework, while the Ni species in Ni/Beta are mostly agglomerated into metallic Ni nanoparticles. The proposed structure of cationic Ni(II) incorporated in BEA zeolite was further investigated by DFT calculations. There are nine inequivalent T sites exist in BEA zeolite, and were labelled according to the zeolite structures database (Supplementary Fig. 12). 26 We first compared the energetics of Ni locate at 4-, 5- and 6-MR and found that Ni prefers to be in the 6-MR ring of BEA zeolite (Supplementary Fig. 13). Three 6-MRs have highly similar Ni(II)-bound sites and ring A1 is described here (Supplementary Fig. 14 and Fig. 2 c). The 6-MR with two aluminium T-sites (anionic AlO 4 tetrahedra) shows that for BEAs with a Si/Al ratio greater than 10, there are three possible configurations for these aluminium T-sites (Si/Al ratios greater than 25 are used here). 27 We further evaluate the effect of aluminium configuration on the resulting Ni(II)-bound site (Fig. 2 d), including T4/T4’ and T8/T8’, which bind Ni(II) with two neutral Si O Si ligands and two anionic Si O Al ligands, and T6/T6’, which binds Ni(II) with four anionic Si O Al ligands. T6/T6’ binds Ni(II) with four anionic Si O Al ligands is the most stable configuration (Supplementary Table 4). Notably, the Ni sites are accessible from 12-MRs of Beta zeolite (Supplementary Fig. 12), which is beneficial for the catalytic interaction between Ni active sites and reaction substrates. In addition, as shown in Fig. 2 e, the bond lengths of the Ni atom with the surrounding O atoms are 1.91, 2.05, 1.91 and 2.04 Å, respectively, which are consistent with EXAFS fitting results. Moreover, the charge density difference of Ni 1 @Beta shows remarkable electron transfer from Ni atom to the first coordinated O atoms due to the formation of Ni-O band (Fig. 2 f and Supplementary Table 5). The isosurface map of interaction region indicator (IRI) performed using the Multiwfn 3.8 (dev) code 28 further reveals that the isolated Ni sites are stabled through bonding to oxygen atoms in the framework of Beta zeolite (Supplementary Fig. 15). In brief, we have successfully prepared isolated Ni species incorporated into the Beta zeolite. All characterizations validate that isolated, distorted tetrahedral Ni species are situated in the center of 6-MRs of zeolite Beta and stabilized by four framework oxygen atoms. Benefiting from the good dispersion of Ni atoms, the unique structure of a coordination environment, and the specific electronic configuration of Ni species, Ni 1 @Beta, upholding the isolated Ni sites combined with the specific zeolite microenvironment, could afford a unique performance in selective hydrogenation reactions. 29 – 31 Catalyst performance and stability. The catalytic hydrogenation of FF into FAL is one of the important reactions to convert biomass-derived compounds into value-added chemicals and fuels. 32 – 35 Heterogeneous non-noble Ni-based catalysts have shown good FF hydrogenation ability, but the major challenge comes from the over-hydrogenation of FAL, often leading to a low FAL selectivity. 36 , 37 The selective hydrogenation of FF into FAL was performed under batch conditions with isopropanol as the solvent to evaluate the catalytic performance of Ni 1 @Beta and Ni/Beta (Supplementary Table 6 and Fig. 3 ). FAL, tetrahydrofurfuryl alcohol (THFA), furfural diisopropyl acetal (FDA), and furfuryl isopropyl ether (FIE) are observed as the main products. The support of Beta possesses limited activity, with an FF conversion of 5.2% after 1 h (Supplementary Table 6, entry 1). After the Ni supported by the wet impregnation method, the as-obtained Ni/Beta catalyst affords an FF conversion of 57.6% and a FAL yield of 41.5% after 1 h, with a turnover frequency (TOF) of 37.6 h − 1 , calculated as the converted number of FF (mol) per Ni site (mol) per unit time (h) at a low conversion level of 20.8% (Fig. 3 b and Supplementary Table 6, entry 7). Comparatively, the Ni 1 @Beta prepared by the in situ two-step hydrothermal strategy displays a marked increase in activity than the Ni/Beta, with an FF conversion of 93.7% and a FAL yield of 85.8%, referring to a TOF of 114.1 h − 1 (Fig. 3 b and Supplementary Table 6, entry 8), which is much higher than the state-of-the-art Ni-based heterogeneous catalysts under similar reaction conditions (Fig. 3 c and Supplementary Table 7). 36 , 38 – 44 To the best of our knowledge, such high activity and FAL yield are rarely observed for a supported Ni catalyst. SACs with the high atom utilization, as well as a unique configuration has provided an enhanced performance. Moreover, a larger amount of spillovered hydrogen (529°C, Supplementary Fig. 8) could be determined for Ni 1 @Beta than for Ni/Beta, implying the atomically dispersed Ni cations within Ni 1 @Beta could improve hydrogenation performance markedly by facilitating the spillover of active hydrogen. 45 , 46 As shown in Fig. 3 b, when increasing the reaction time to 2 h, Ni 1 @Beta shows a full conversion of FF, with a FAL yield of 88.2% and a THFA yield of 5.6%. As for Ni/Beta, the FF conversion increases to 87.1%, with a FAL yield of 53.0% and a THFA yield of 25.3%. These results indicate that the hydrogenation of FAL to THFA can be effectively suppressed for Ni 1 @Beta owing to the efficient modulation of Ni species in zeolite micro-environment. In order to further confirm the specificity of zeolite structure, we synthesized Ni particles supported on an open-structure support (Ni/SiO 2 , Supplementary Table 6, entry 6), which exhibits a good capacity of over-hydrogenation, with a THFA selectivity of 22.0%, which is much higher than Ni/Beta (9.6%) and Ni 1 @Beta (2.5%) at a comparable low FF conversion of ~ 20.0%. The main reason could be attributed to the lack of constrained environments and proper modulation of electronic configuration for Ni species, resulting in the loss in FAL selectivity owing to consecutive hydrogenation of FAL into THFA. The stability of Ni 1 @Beta and Ni/Beta is further examined by performing consecutive runs in the selective hydrogenation of FF into FAL. Ni 1 @Beta or Ni/Beta after the reaction was filtered, washed with isopropanol and dried at 60°C overnight. As shown in Fig. 3 d, Ni 1 @Beta shows no apparent decrease in the FF conversion, from an initial 70.7 to 68.7% upon five consecutive runs. The yield of FAL is well-maintained at a similar level of 64–67% upon catalysis. No notable changes in activity and selectivity confirm no apparent deactivation, indicating the excellent stability of Ni 1 @Beta. In contrast, an obvious deactivation is observed with Ni/Beta, with a distinct drop in FF conversion from 68.7–10.2% and the FAL yield from 52.8–7.6% through five consecutive runs (Fig. 3 e). To track the possible changes of the catalysts, XRD, ICP-OES, and STEM were conducted for the spent Ni 1 @Beta and Ni/Beta. After five consecutive runs, XRD results reveal that both Ni 1 @Beta and Ni/Beta retain the BEA zeolite structure integrity during recycling tests (Supplementary Fig. 16). ICP-OES shows a decrease in Ni content from 1.10 to 0.74 wt % for the spent Ni/Beta (Supplementary Table 1). Moreover, the mean size of Ni nanoparticles in Ni/Beta increases from ~ 7.6 to ~ 12.4 nm after five consecutive runs (Supplementary Fig. 17a, b). These results suggest that the deactivation of Ni/Beta may be due to the combined effects of Ni leaching and aggregation. Conversely, no metal leaching is detected for the spent Ni 1 @Beta (Supplementary Table 1). In addition, STEM image shows no observable agglomeration of metal species for the spent Ni 1 @Beta, and AC-HAADF-STEM images of the spent Ni 1 @Beta further reveals that Ni species maintain as isolated Ni atoms (Supplementary Fig. 17c, d), corroborating again the excellent stability of Ni 1 @Beta in the selective hydrogenation of FF. Insights into catalytic behavior. The remarkable catalytic performance of Ni 1 @Beta closely related to the electronic properties of isolated Ni sites. H 2 temperature-programmed reduction (H 2 -TPR) was performed for Ni 1 @Beta and Ni/Beta (Fig. 4 a). For Ni/Beta, a broad H 2 -consumption peak at around 464°C can be assigned to the reduction of NiO to metallic Ni. 47 , 48 For Ni 1 @Beta, a signal at a higher temperature of 650°C, can be attributed to the reduction of isolated Ni cations located in the zeolite pores, indicating a stronger metal-support interaction in Ni 1 @Beta than that in Ni/Beta. 49,50 The XPS analyses were further used to characterize the electronic states of Ni species in Ni/Beta and Ni 1 @Beta. Prior to the XPS measurement, both samples were sputtered with Ar + ion for two minutes to etch the surface oxide layer. The XPS spectrum of the Ni 2p 3/2 for Ni 1 @Beta catalyst (Fig. 4 b) only shows one characteristic peak at 856.1 eV, which is attributed to the Ni 2+ species. 错误!未找到引用源。 This again in line with XAS results that the Ni species of Ni 1 @Beta bear the positive charge. As for Ni/Beta, two main peaks center at 852.5 and 855.8 eV are observed in Ni 2p 3/2 signal, corresponding to Ni 0 and Ni 2+ species, respectively. 51 , 52 Notably, the peak of Ni 2+ in Ni 1 @Beta is shifted to a slightly higher binding energy compared to Ni/Beta. This positive shift indicates a buidup of positive charges on the Ni species, which also points to an enhanced electron interaction between Ni and O atoms (Supplementary Fig. 18). Recently, Li and co-workers have demonstrated that the electron-rich Pd single-atom sites would promote the dissociation of H 2 and the adsorption of substrate on Pd sites, which afforded enhanced performance in the semi-hydrogenation of a broad range of substrates. 53 To further characterize the electronic configuration of Ni species in Ni/Beta and Ni 1 @Beta, FT-IR-CO was performed at a low temperature of -170°C with stepwise adsorption of CO (Fig. 4 c and 4 d). As shown in Supplementary Fig. 19, the vibrational features of adsorbed-CO at around 2170 cm − 1 and 2129 cm − 1 over Beta zeolite, are associated with carbonyls formed with the participation of Na + ions. 54–56 For the Ni 1 @Beta (Fig. 4 c), in addition to the CO adsorption on Na + , a new peak appears at 2202 cm − 1 , which can be assigned to adsorption of CO on isolated Ni 2+ sites according to previous reports. 57 , 58 In the case of Ni/Beta (Fig. 4 d), the adsorption of CO on Ni produces two additional bands centred at ~ 2020 and ~ 1900 cm − 1 , besides the CO signals observed for Ni 1 @Beta. The former is attributed to linear-adsorbed CO on metallic Ni nanoparticles and the latter is ascribes to bridging Ni-CO species. 59 , 60 Notably, such two signals were not apparent for Ni 1 @Beta, further confirming that the Ni species in Ni 1 @Beta are atomically dispersed. In addition, as for Ni/Beta, there also exits a smaller peak at 2202 cm − 1 , indicating the presence of Ni 2+ species in Ni/Beta, consistent with the XPS results. Base on the above results, the excellent catalytic performance of Ni 1 @Beta in the selective hydrogenation of FF into FAL is not only related to the successful incorporation of Ni single-atoms but also to the appropriate modulation of the coordination environment of Ni atoms by the restricted zeolite micro-environment. Zeolite-tailored metal incorporation can efficiently restrict the migration of isolated Ni species by spatial restriction of the confined micro-environment, preventing metal sintering and leaching efficiently during catalysis. Besides, the confined environment of the zeolite could also induce the formation of a unique coordinated spatial structure (Ni-O 4 sites), which efficient modulate the electronic configuration of the isolated Ni species (bear a positive charge of ~ Ni 2+ ) and exhibit specific adsorption and desorption to FF and FAL, facilitating hydrogen spillover and thus enhancing performance in the selective hydrogenation of FF into FAL. 25 , 61 , 62 Conclusions In summary, a facile in situ hydrothermal synthesis strategy is developed for precisely incorporating isolated Ni species into Beta zeolite without using any chelating agent for stabilizing Ni metals for the first time. AC-HAADF-STEM and XAS analyses, combined with DFT calculations, reveal the fine structure of the as-prepared Ni 1 @Beta, where the atomically dispersed Ni 2+ species are stabilized by the surrounding four oxygen atoms in six-membered rings. Benefiting from unique coordination environment and maximum atomic utilization of incorporated Ni single-atoms within Beta zeolite, the as-obtained Ni 1 @Beta catalyst exhibits excellent catalytic activity and selectivity in the selective hydrogenation of FF into FAL, with a TOF value up to 114.1 h -1 , surpassing that of Ni/Beta prepared by impregnation method and those of previously reported Ni-based heterogeneous catalysts. Additionally, this confinement structure and coronation environment significantly improve the stability and sintering resistance of Ni 1 @ Beta. These findings afford an efficient strategy for the efficientfabrication of isolated non-noble metal atoms within zeolite structure, which will be of great aid and potential for the rational design of active and selective zeolitic materials for hydrogen-assisted biomass valorization and other energy-related reactions. Methods Materials for catalyst synthesis. Tetraethylammonium hydroxide (TEAOH, 25 wt% in H 2 O), silica gel (99 wt% SiO 2 ,), furfural (99%) and isopropanol (99%) were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. Sodium hydroxide (NaOH, 99%) was obtained from Sinopharm Chemical Reagent Co., Ltd. Sodium metaaluminate (NaAlO 2 , 45 wt% Al 2 O 3 ) was obtained from Tianjin Jinke Fine Chemical Research Institute. Nickel (II) nitrate hexahydrate (Ni(NO 3 ) 2 ·6H 2 O, 98%) was obtained from Tianjin Fuchen Chemical Reagent Factory. Above materials were used without further purification. Synthesis of Beta zeolite via a hydrothermal method. In a typical process, 27.9 g TEAOH and 0.45 g NaOH were added to 11.48 g deionized water, and stirred until a clear solution was formed. Subsequently, 0.8 g NaAlO 2 was added and stirring was continued for 30 min. Then, 15 g silica gel was slowly added to the above solution and stirred for 3 h to a resulting alumino-silicate gel. The resulting gel was transferred into a 100 mL Teflon lining stainless-steel autoclave, placed in an oven at 140 °C and crystallized for 48 h. After crystallization, the autoclave was quenched with flowing water, and the solid products were separated by centrifuge, and washed with deionized water until the pH value of filtrate was ~ 7. After that, the solid product was transferred to a 100 °C oven and dried for 12 h. Finally, the Beta zeolite was obtained by calcination in the air at 550 °C for 6 h (heating rate: 2 °C min -1 ). Synthesis of Ni 1 @Beta via an in situ two-step hydrothermal method . The alumino-silicate gel with the same makeup as of Beta zeolite was placed in an autoclave at 100 °C for 24 h, and then the autoclave was cooled to ambient temperature. Next, 0.75 g Ni(NO 3 ) 2 precursor dissolved into 1 g deionized water was introduced into the contents of the autoclave. The autoclave was sealed again, heated to 140 °C and kept at this temperature for 36 h. The as obtained solid product was filtered, washed with water for several times, and then dried at 100 °C in the oven overnight, followed by calcination at 550 °C for 6 h. Finally, reduced at 30 mL min -1 10% H 2 /N 2 flow at 500 °C (heating rate: 5 °C min -1 ) for 2 h. Before exposure to air, all the samples were passivated at 30 °C for 1 h under 30 mL min -1 1% O 2 /N 2 flow. Synthesis of Ni/Beta-HT via an in situ one-step hydrothermal method. Ni/Beta-HT was prepared using the same alumino-silicate gel composition with Ni(NO 3 ) 2 precursor of Ni 1 @Beta above. In a typical synthesis, the obtained gel was prepared and directly put in a 140 °C oven for hydrothermal synthesis for 48 h without the first step of the nucleation process. The solid product was filtered, washed with H 2 O for several times, and dried in an oven at 100 °C overnight, and calcined at 550 °C for 6 h. Finally, the sample was reduced at 500°C for 2 h and passivated at 30 °C for 1 h. Synthesis of Ni/Beta and Ni/SiO 2 via impregnation method. Ni/Beta and Ni/SiO 2 were prepared by wet impregnation method with Ni(NO 3 ) 2 solution. The samples were dried at 100 °C overnight. Followed by calcination, reduction and passivation, the steps are the same as Ni 1 @Beta. Catalyst evaluation. The hydrogenation of furfural in a liquid-phase was carried out in a 100 mL autoclave. In a typical procedure, 0.3 g furfural was mixed with 23.56 g isopropanol, and then 0.3 g catalyst was added. The reactor was sealed, and then purged with N 2 and H 2 for three times, repectively. Next, the autoclave was pressurized with H 2 and subsequently heated to the reaction temperature. After reaction, the autoclave was rapidly cooled and the products were collected using a 0.22 μm filter membrane and analyzed by Agilent GC 7890B (HP-5 column) with N,N-Dimethylformamide (DMF) as an internal standard. The reusability test of Ni 1 @Beta and Ni/Beta catalyst was investigated under the furfural conversion at ~ 70%; the catalysts after each reaction were separated by centrifugation, washing with isopropanol and dried at 60 °C for 12 h. Catalyst characterization. X-ray diffraction (XRD) detection was conducted using a Bruker D8 Advance diffractometer with Cu-Kα radiation source (40 kV, 40 mA). The Si/Al molar ratio of zeolite samples were determined by the X-ray fluorescence (XRF), which was conducted on a PANalytical AxiosMAX analyzer. The inductively coupled plasma-optical emission spectroscopy (ICP-OES) was performed on a PerkinElmer Optima 7300V to obtain chemical compositions of zeolite samples. The scanning electron microscopy (STEM) images was recorded on a Gemini SEM 300 field-emission microscope. The texture properties of zeolite samples were recorded using a Kubo X1000 setup operating at -196 °C. Before sorption measurements, samples were treated at 350 °C for 4 h under vacuum to eliminate adsorbed substances. The aberration-corrected scanning transmission electron microscopy (AC-STEM) images performed on on a JEOL JEM-ARM200F with a CEOS probe corrector at 200 kV. For the high-angle annular dark-field (HAADF) imaging, identical convergence and collection angle ranges were implemented. Energy dispersive X-ray spectra (EDX-mapping) were collected with a JEOL Oxford X-MaxN 80 T silicon drift detector. The temperature-programmed desorption of hydrogen (H 2 -TPD) and H 2 temperature-programmed reduction (H 2 -TPR) were conducted on a chemisorption instrument (Huasi DAS-7000), which equipped with a TCD detector. For H 2 -TPD, about 100 mg zeolite samples were firstly treated in the N 2 flow (30 ml min -1 ) at 400 °C for 1 h, and then cooled down to room temperature. Next, the zeolite samples were saturated with 10% H 2 /N 2 flow (30 mL min -1 ) and then purged with N 2 to eliminated the weakly adsorbed species. Finally, the H 2 -TPD profile was recorded from 30 °C to 800 °C (5 °C min -1 ). For H 2 -TPR experiments, about 50 mg unreduced zeolite samples were dehydrated at 400 °C for 1 h and cooled down to 50 °C in flowing N 2 (30 mL min -1 ). Then the H 2 -TPR spectra were recorded in the 10 % H 2 /N 2 (30 mL min -1 ) flow by increasing reduction temperature from 50 °C to 800 °C (5 °C min -1 ). X-ray absorption spectroscopy (XAS), encompassing X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy at the Ni K-edge, were obtain on Beijing Synchrotron Radiation Facility (BSRF) with 1W1B beamlines at 250 mA. The spectra were recorded in fluorescence mode on a self-supported wafer at ambient temperature. The Ni foil was utilized for the calibration of energy. The XAFS datas were further analyzed using Athena and Artemis modules, which equipped with the IFEFFIT software package. All calculations are implemented using the GGA-PBE electronic exchange-related functions from the Vienna ab initio simulation package (VASP 5.4.4). The cutoff energy was fixed at 400 eV. The Brillouin zone was sampled using 1×1×1 gamma points. The force was kept below 0.05 eV Å -1 in the optimization of all structures. As for the analysis and calculation of IRI maps, Multiwfn 3.8 (dev) software was used. X-ray photoelectron spectra (XPS) were conducted at a Thermo Scientific K-Alpha apparatus using Al Kα radiation. Before detection, the sample were etched by Ar + ions of 2 min. Binding energies (BE) were calibrated by adjusting the BE of the C1s peak to 284.8 eV. Fourier transform infrared (FT-IR) spectra after CO adsorption were recorded with a Bruker Tensor II instrument. Before spectral acquisition, samples were pressed into self-supported wafers and placed inside the self-designed cell, then treated at 350 °C for 1 h in N 2 flow, and continuously reduced at H 2 flow for 1 h. Subsequently, the temperature of the IR cell was cooled to 30 °C with circulating water and evacuated to 10 -8 bar. The IR cell was then continued to cool to -170 °C with liquid N 2 and the spectrum was recorded at this point as a background signal. CO adsorption was studied at -170 °C by gradually increasing the pressure (from 0 to 2.0 mbar). Declarations Data availability The data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request. Acknowledgements This work is supported by the National Key Research and Development Program of China (2022YFB3805602), CNPC Innovation Found (2021DQ02-0702), National Natural Science Foundation of China (22078316 and 22479082), the funding of Inner Mongolia University (10000-23112101/081) and the funding of Inner Mongolia Youth Science and Technology Talents (NJYT24019). Author contributions M.L. conducted the catalyst preparation, activity tests and most of catalyst characterizations. C.M., Y.N. and Y.Z. conducted and analysed FT-IR-CO experiments. Y.F. and W.S. performed the DFT calculations. W.W. and J.L. collected the high-resolution STEM measurements. S.C. performed XAS experiments. Z.W. and W.L. conceived the ideas and designed the project. M.L., Z.W. and W.L. wrote the paper with collective contributions and discussion from all authors. All authors approved the final version of the manuscript. Competing financial interests The authors declare no competing financial interests. Additional information Supplementary information is available in the online version of the paper. Correspondence and requests for materials should be addressed to Z.W. or W.L. Reprints and permissions information is available online at www.nature.com/reprints. Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. References Zhang, Q., Gao, S. & Yu, J. Metal Sites in Zeolites: Synthesis, characterization, and catalysis. Chem. Rev . 123 , 6039-6106 (2022). Wu, Q., Xu, C., Zhu, L., Meng, X. & Xiao, F.-S. Recent strategies for synthesis of metallosilicate zeolites. Catal. Today 390-391 , 2-11 (2022). Yang, J. et al. Enhanced catalytic performance through in situ encapsulation of ultrafine Ru clusters within a high-aluminum zeolite. ACS Catal. 12 , 1847-1856, (2022). Cao, P. et al. Zeolite-encapsulated Cu nanoparticles for the selective hydrogenation of furfural to furfuryl alcohol. ACS Catal. 11 , 10246-10256, (2021). Ma, B. et al. Implanting colloidal nanoparticles into single-crystalline zeolites for catalytic dehydration. Angew. Chem. Int. Ed. 63 , e202403245 (2024). Lu, Y. B., Zhang, Z. H., Wang, H. M. & Wang, Y. Toward efficient single-atom catalysts for renewable fuels and chemicals production from biomass and CO. Appl Catal B-Environ. 292 , 120162-120199 (2021). Liang, X., Fu, N. H., Yao, S. C., Li, Z. & Li, Y. D. The progress and outlook of metal single-atom-site catalysis. J. Am. Chem. Soc. 144 , 18155-18174 (2022). Jing, W. et al. Surface and interface coordination chemistry learned from model heterogeneous metal nanocatalysts: From atomically dispersed catalysts to atomically precise clusters. Chem. Rev , 1 23 , 5948-6002 (2023). Cheng, Q. et al. Highly efficient and stable methane dry reforming enabled by a single-site cationic Ni catalyst. J. Am. Chem. Soc. 145 , 25109-25119 (2023). Yu, Z. et al. Suppressing metal meaching and sintering in hydroformylation reaction by modulating the coordination of Rh single atoms with reactants. J. Am. Chem. Soc. 146 , 11955-11967 (2024). Chai, Y. C. et al. Control of zeolite pore interior for chemoselective alkyne/olefin separations. Science 368 , 1002-1006 (2020). Liu, M., Miao, C. & Wu, Z. Recent advances in the synthesis, characterization, and catalytic consequence of metal species confined within zeolite for hydrogen-related reactions. Ind. Chem. & Mater. 2 , 57-84 (2024). Huang, W. X. et al. Low-temperature transformation of methane to methanol on PdO single sites anchored on the internal surface of microporous silicate. Angew. Chem. Int. Ed. 55 , 13441-13445 (2016). Xu, K. et al. Partial hydrogenation of anisole to cyclohexanone in water medium catalyzed by atomically dispersed Pd anchored in the micropores of zeolite. Appl. Catal. B: Environ. 341 , 123244-123254 (2024). Zecevic, J., van der Eerden, A. M. J., Friedrich, H., de Jongh, P. E. & de Jong, K. P. Heterogeneities of the nanostructure of platinum/zeolite Y catalysts revealed by electron tomography. ACS Nano 7 , 3698-3705 (2013). Sun, Q. M. et al. Zeolite-encaged single-atom rhodium catalysts: Highly-efficient hydrogen generation and shape-selective tandem hydrogenation of nitroarenes. Angew. Chem. Int. Ed. 58 , 18570-18576 (2019). Deng, X. et al. Zeolite-encaged isolated platinum ions enable heterolytic dihydrogen activation and selective hydrogenations. J. Am. Chem. Soc. 143 , 20898-20906 (2021). Goel, S., Zones, S. I. & Iglesia, E. Encapsulation of metal mlusters within MFI via interzeolite transformations and direct hydrothermal syntheses and catalytic consequences of their confinement. J. Am. Chem. Soc. 136 , 15280-15290 (2014). Wu, Z. J., Goel, S., Choi, M. & Iglesia, E. Hydrothermal synthesis of LTA-encapsulated metal clusters and consequences for catalyst stability, reactivity, and selectivity. J. Catal. 311 , 458-468 (2014). Goel, S., Wu, Z., Zones, S. I. & Iglesia, E. Synthesis and catalytic properties of metal clusters encapsulated within small-pore (SOD, GIS, ANA) zeolites. J. Am. Chem. Soc. 134 , 17688-17695 (2012). Sung, J. K. et al. General synthetic route toward highly dispersed metal clusters enabled by poly(ionic liquid)s. J. Am. Chem. Soc. 139 , 8971-8976 (2017). Wang, C. L. et al. Hydrolysis of ammonia-borane over Ni/ZIF-8 nanocatalyst: High efficiency, mechanism, and controlled hydrogen release. J. Am. Chem. Soc. 139 , 11610-11615 (2017). Liu, Y. et al. Embedding high loading and uniform Ni nanoparticles into silicalite-1 zeolite for dry reforming of methane. Appl. Catal.s B-Environ. 307 , 121202-121210 (2022). Ikuno, T. et al. Methane Oxidation to methanol catalyzed by Cu-Oxo clusters stabilized in NU-1000 metal-organic framework. J. Am. Chem. Soc. 139 , 10294-10301 (2017). Liu, W. G. et al. A durable nickel single-atom catalyst for hydrogenation reactions and cellulose valorization under harsh conditions. Angew. Chem. Int. Ed. 57 , 7071-7075 (2018). IZA-SC. International Zeolite Association. Database of Zeolite Structures; http://www.izastructure.org/databases. Snyder, B. E. R. et al. The active site of low-temperature methane hydroxylation in iron-containing zeolites. Nature 536 , 317-321 (2016). Lu, T. & Chen, F. Multiwfn: A multifunctional wavefunction analyzer. J. Comput. Chem. 33 , 580-592 (2011). Chai, Y. C. et al. Acetylene-selective hydrogenation catalyzed by cationic confined in zeolite. J. Am. Chem. Soc. 141 , 9920-9927 (2019). Wang, J. et al. Isolated palladium atoms dispersed on silicoaluminophosphate-31 (SAPO-31) for the semihydrogenation of alkynes. ACS Appl. Nano Mater. 4 , 861-868 (2020). Fan, Y. et al. Efficient single-atom Ni for catalytic transfer hydrogenation of furfural to furfuryl alcohol. J. Mater. Chem. A 9 , 1110-1118 (2021). Sievers, C. et al. Acid-catalyzed conversion of sugars and furfurals in an ionic-liquid phase. ChemSusChem 2 , 665-671 (2009). Mariscal, R., Maireles-Torres, P., Ojeda, M., Sádaba, I. & Granados, M. L. Furfural: a renewable and versatile platform molecule for the synthesis of chemicals and fuels. Energ Environ. Sci. 9 , 1144-1189 (2016). Bohre, A., Dutta, S., Saha, B. & Abu-Omar, M. M. Upgrading furfurals to drop-in biofuels: An overview. ACS Sustain. Chem. Eng. 3 , 1263-1277 (2015). Joo, S. H. et al. Ordered nanoporous arrays of carbon supporting high dispersions of platinum nanoparticles. Nature 412 , 169-172 (2001). Jia, P., Lan, X., Li, X. & Wang, T. Highly active and selective NiFe/SiO 2 bimetallic catalyst with optimized solvent effect for the liquid-phase hydrogenation of furfural to furfuryl alcohol. ACS Sustainable Chem. & Eng. 6 , 13287-13295 (2018). Chen, S., Wojcieszak, R., Dumeignil, F., Marceau, E. & Royer, S. How catalysts and experimental conditions determine the selective hydroconversion of furfural and 5-hydroxymethylfurfural. Chem. Rev. 118 , 11023-11117 (2018). Kotbagi, T. V., Gurav, H. R., Nagpure, A. S., Chilukuri, S. V. & Bakker, M. G. Highly efficient nitrogen-doped hierarchically porous carbon supported Ni nanoparticles for the selective hydrogenation of furfural to furfuryl alcohol. RSC Adv. 6 , 67662-67668 (2016). Lin, W. et al. Surface Synergetic Effects of Ni-ReO for promoting the mild hydrogenation of furfural to tetrahydrofurfuryl alcohol. ACS Catal. 13 , 11256-11267 (2023). Liu, L., Lou, H. & Chen, M. Selective hydrogenation of furfural to tetrahydrofurfuryl alcohol over Ni/CNTs and bimetallic Cu Ni/CNTs catalysts. Int. J. Hydrogen Energy 41 , 14721-14731 (2016). Rodiansono, R., Hara, T., Ichikuni, N. & Shimazu, S. Development of nanoporous Ni-Sn alloy and application for chemoselective hydrogenation of furfural to furfuryl alcohol. Bull. Chem. React. Eng. Catal. 9 , 53-59 (2014). Zhang, J., Mao, D., Zhang, H. & Wu, D. Improving furfural hydrogenation selectivity by enhanced Ni-TiO 2 electronic interaction. Appl. Catal. A: Gen. 660 , 119206-119217 (2023). Wu, J. et al. Efficient and versatile CuNi alloy nanocatalysts for the highly selective hydrogenation of furfural. Appl. Catal. B: Environ. 203 , 227-236 (2017). Yang, Y. et al. Aqueous phase hydrogenation of furfural to tetrahydrofurfuryl alcohol on alkaline earth metal modified Ni/Al 2 O 3 . RSC Adv. 6 , 51221-51228 (2016). Tian, Y. J. et al. Template guiding for the encapsulation of uniformly subnanometric platinum clusters in Beta-zeolites enabling high catalytic activity and stability. Angew. Chem. Int. Ed. 60 , 21713-21717 (2021). Wang, L., Ma, Y., Li, H., Luo, W. & Liu, J. Screening support effect of Pt/MOx for selective hydrogenation of cinnamaldehyde. J. Catal. 431 , 115391-115398 (2024). Kostyniuk, A., Bajec, D. & Likozar, B. Catalytic hydrogenation, hydrocracking and isomerization reactions of biomass tar model compound mixture over Ni-modified zeolite catalysts in packed bed reactor. Renew. Ener.g 167 , 409-424 (2021). Moussa, S., Concepción, P., Arribas, M. A. & Martínez, A. The nature of active Ni sites and the role of Al species in the oligomerization of ethylene on mesoporous Ni-Al-MCM-41 catalysts. Appl. Catal. A: Gen. 608 , 117831-117840 (2020). Yan, P. et al. Facile and eco-friendly approach to produce confined metal cluster catalysts. J. Am. Chem. Soc. 145 , 9718-9728 (2023). Maia, A. J., Louis, B., Lam, Y. L. & Pereira, M. M. Ni-ZSM-5 catalysts: Detailed characterization of metal sites for proper catalyst design. J. Catal. 269 , 103-109 (2010). Zhang, Q., Jiang, X., Su, Y., Zhao, Y. & Qiao, B. Catalytic propane dehydrogenation by anatase supported Ni single-atom catalysts. Chin. J. Catal. 57 , 105-113 (2024). Guo, X. W. Hollow zeolite encapsulated Ni-Pt bimetals for sintering and coking resistant dry reforming of methane. J. Mater. Chem. A 3 , 16461-16468 (2015). Liu, H. et al. Encapsulation of Pd single-atom sites in zeolite for highly efficient semihydrogenation of alkynes. J. Am. Chem. Soc. 146 , 24033-24041 (2024). Aleksandrov, H. A. et al. Precise identification of the infrared bands of the polycarbonyl complexes on Ni-MOR zeolite by 12 C 16 O- 13 C 18 O coadsorption and computational modeling. The J. Phys. Chem. C 116 , 22823-22831 (2012). Salla, I., Montanari, T., Salagre, P., Cesteros, Y. & Busca, G. Fourier transform infrared spectroscopic study of the adsorption of CO and nitriles on Na-mordenite: Evidence of a new interaction. J. Phys. Chem. B 109 , 915-922 (2005). Cairon, O. & Bellat, J. P. Macroscopic and molecular insights from CO adsorption on NaY zeolite: A combined FTIR and manometric study. J. Phys. Chem. C 116 , 11195-11199 (2012). Ma, R. et al. Insights into the nature of selective nickel sites on Ni/Al 2 O 3 catalysts for propane dehydrogenation. ACS. Catal. 12 , 12607-12616 (2022). Martínez Gómez-Aldaraví, A., Paris, C., Moliner, M. & Martínez, C. Design of bi-functional Ni-zeolites for ethylene oligomerization: Controlling Ni speciation and zeolite properties by one-pot and post-synthetic Ni incorporation. J. Catal. 426 , 140-152 (2023). Resini, C. et al. An FFIR study of the dispersed Ni species on Ni-YSZ catalysts. Appl. Catal. A-Gen. 353 , 137-143 (2009). Moussa, S., Concepción, P., Arribas, M. A. & Martínez, A. Nature of active nickel sites and initiation mechanism for ethylene oligomerization on heterogeneous Ni-beta catalysts. ACS Catal. 8 , 3903-3912 (2018). Su, H. et al. Grouping effect of single nickel-N sites in nitrogen-doped carbon boosts hydrogen transfer coupling of alcohols and amines. Angew. Chem. Int. Ed. 57 , 15194-15198 (2018). Gu, J. et al. Synergizing metal-support interactions and spatial confinement boosts dynamics of atomic nickel for hydrogenations. Nat. Nanotechnol. 16 , 1141-1149 (2021). Scheme Scheme 1 is available in the Supplementary Files section. Additional Declarations There is NO Competing Interest. Supplementary Files Scheme.docx SupportingInformation.docx Chelating-agent-free incorporation of isolated Ni single-atoms within BEA Zeolite for enhanced biomass hydrogenation Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5796369","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":400053058,"identity":"10171435-9379-4ae4-86d1-4d9fc3703961","order_by":0,"name":"Wenhao Luo","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAApUlEQVRIiWNgGAWjYFAC5gYGhgoJMFOCSC2MQC1nSNbC2MZAghaDA4xtEh/nWUQbHGA+eJuHwS6PKC2SM7dJ5G44wJZszcOQXExQixlQizQvWAuPmTQPw4HEBuK0zAFp4f9GipYGsC1sxGmxP8zYbDnjmETuzMNsxpZzDJIJa5Fsbz5440NNXW7f8eaHN95U2BHWwsCMwjAgqH4UjIJRMApGATEAAPZ+N0lSoEN9AAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0003-1941-3799","institution":"Inner Mongolia University","correspondingAuthor":true,"prefix":"","firstName":"Wenhao","middleName":"","lastName":"Luo","suffix":""},{"id":400053059,"identity":"896b75bd-8dfb-41d0-bce5-771bcea778a8","order_by":1,"name":"Meng Liu","email":"","orcid":"","institution":"China University of Petroleum-Beijing","correspondingAuthor":false,"prefix":"","firstName":"Meng","middleName":"","lastName":"Liu","suffix":""},{"id":400053060,"identity":"32006d6e-adc1-4124-aac4-2ce6b1af3e04","order_by":2,"name":"Caixia Miao","email":"","orcid":"","institution":"China University of Petroleum-Beijing","correspondingAuthor":false,"prefix":"","firstName":"Caixia","middleName":"","lastName":"Miao","suffix":""},{"id":400053061,"identity":"42be1425-55e7-4881-ae20-e1646ee078bc","order_by":3,"name":"Yumeng Fo","email":"","orcid":"","institution":"China University of Petroleum-Beijing","correspondingAuthor":false,"prefix":"","firstName":"Yumeng","middleName":"","lastName":"Fo","suffix":""},{"id":400053062,"identity":"f3259f3e-000b-4fbc-83b9-54728c998606","order_by":4,"name":"Wenxuan Wang","email":"","orcid":"","institution":"Inner Mongolia University","correspondingAuthor":false,"prefix":"","firstName":"Wenxuan","middleName":"","lastName":"Wang","suffix":""},{"id":400053063,"identity":"2e96c90b-5c6a-4e7e-8a84-43f943d3fe01","order_by":5,"name":"Yao Ning","email":"","orcid":"","institution":"China University of Petroleum-Beijing","correspondingAuthor":false,"prefix":"","firstName":"Yao","middleName":"","lastName":"Ning","suffix":""},{"id":400053064,"identity":"9a516f3d-c84b-4f67-a00e-15f02294dbdd","order_by":6,"name":"Sheng-Qi Chu","email":"","orcid":"https://orcid.org/0000-0002-6334-5095","institution":"Institute of High Energy Physics","correspondingAuthor":false,"prefix":"","firstName":"Sheng-Qi","middleName":"","lastName":"Chu","suffix":""},{"id":400053065,"identity":"53b1cc67-6549-4238-acb8-e0939f36d326","order_by":7,"name":"Weiyu Song","email":"","orcid":"","institution":"China University of Petroleum (Beijing)","correspondingAuthor":false,"prefix":"","firstName":"Weiyu","middleName":"","lastName":"Song","suffix":""},{"id":400053066,"identity":"d4cde89c-7b95-4173-a8b6-fadedb2ac129","order_by":8,"name":"Ying Zhang","email":"","orcid":"","institution":"China University of Petroleum-Beijing","correspondingAuthor":false,"prefix":"","firstName":"Ying","middleName":"","lastName":"Zhang","suffix":""},{"id":400053067,"identity":"34c69042-14ff-42f7-9be6-c399cf4892bb","order_by":9,"name":"Jian Liu","email":"","orcid":"https://orcid.org/0000-0002-5114-0404","institution":"Inner Mongolia University","correspondingAuthor":false,"prefix":"","firstName":"Jian","middleName":"","lastName":"Liu","suffix":""},{"id":400053068,"identity":"fb72a463-da73-47a0-a01b-3b6f0c864688","order_by":10,"name":"Zhijie Wu","email":"","orcid":"","institution":"China University of Petroleum, Beijing","correspondingAuthor":false,"prefix":"","firstName":"Zhijie","middleName":"","lastName":"Wu","suffix":""}],"badges":[],"createdAt":"2025-01-09 12:10:32","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5796369/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5796369/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":73830728,"identity":"d0048d3c-da11-4c0b-bb84-de4db76748c8","added_by":"auto","created_at":"2025-01-15 06:17:38","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":523916,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eElectron microscopy analyses of the Ni\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e@Beta. (a)\u003c/strong\u003e Low magnification STEM image, \u003cstrong\u003e(b, c)\u003c/strong\u003e High magnification STEM image, \u003cstrong\u003e(d)\u003c/strong\u003e Elemental mappings for Si, Al and Ni, \u003cstrong\u003e(e)\u003c/strong\u003e AC-HAADF-STEM image and \u003cstrong\u003e(f)\u003c/strong\u003e its magnified AC-HAADF-STEM images of selected regions. Isolated Ni atoms are marked in white circles.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5796369/v1/77774f483b0b513b19ca69b5.png"},{"id":73830278,"identity":"17bf7357-a827-4a95-9487-53d9b4fb8e25","added_by":"auto","created_at":"2025-01-15 06:09:38","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":267840,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eStructure of Ni\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e@Beta. (a)\u003c/strong\u003e Ni K-edge XANES spectra and \u003cstrong\u003e(b)\u003c/strong\u003e FT magnitude of the k\u003csup\u003e2\u003c/sup\u003e-weighted EXAFS in R space for Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta catalysts with comparison to a Ni foil and a NiO reference. \u003cstrong\u003e(c)\u003c/strong\u003e 6-MR motifs found in BEA zeolite. \u003cstrong\u003e(d)\u003c/strong\u003e Different configurations of Al sites in A1 ring. \u003cstrong\u003e(e)\u003c/strong\u003e The distances between the Ni atom and the first coordinated O atoms. \u003cstrong\u003e(f)\u003c/strong\u003e Electron charge density difference plot of Ni\u003csub\u003e1\u003c/sub\u003e@Beta with the most stable structure. Yellow and green colors indicate the accumulation and depletion of electron density, respectively.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5796369/v1/04a957f920c86b34e1d368d5.png"},{"id":73830729,"identity":"6f2c6d50-fc18-4182-8029-ad27430059fd","added_by":"auto","created_at":"2025-01-15 06:17:38","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":167665,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCatalytic performance and recyclability of Ni\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e@Beta and Ni/Beta (a)\u003c/strong\u003e Typical reaction networks for furfural hydrogenation. \u003cstrong\u003e(b)\u003c/strong\u003e Catalytic hydrogenation of furfural with different catalysts. \u003csup\u003ea\u003c/sup\u003eReaction conditions: 0.3 g FF, 23.56 g isopropanol, 0.3 g catalyst, 10 bar H\u003csub\u003e2\u003c/sub\u003e, 110 °C, 1 h, 1000 rpm. \u003csup\u003eb\u003c/sup\u003eReaction conditions: 0.3 g FF, 23.56 g isopropanol, 0.3 g catalyst, 10 bar H\u003csub\u003e2\u003c/sub\u003e, 110 °C, 2 h, 1000 rpm. \u003cstrong\u003e(c)\u003c/strong\u003e Literature survey of Ni-based heterogeneous catalysts for furfural hydrogenation.\u003csup\u003e36,38-44\u003c/sup\u003e \u003cstrong\u003e(d)\u003c/strong\u003e Recyclability of Ni\u003csub\u003e1\u003c/sub\u003e@Beta in the selective hydrogenation of furfural. Reaction conditions: 0.3 g FF, 23.56 g isopropanol, 0.1 g catalyst, 10 bar H\u003csub\u003e2\u003c/sub\u003e, 110 °C, 1 h, 1000 rpm. (e) Recyclability of Ni/Beta in the selective hydrogenation of furfural. Reaction conditions: 0.3 g FF, 23.56 g isopropanol, 0.4 g catalyst, 10 bar H\u003csub\u003e2\u003c/sub\u003e, 110 °C, 1 h, 1000 rpm.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5796369/v1/bfa60d8ca5b9c24841e24144.png"},{"id":73830730,"identity":"14cf197b-f461-4dce-a011-6eea328f9a04","added_by":"auto","created_at":"2025-01-15 06:17:38","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":173294,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCharacterization of Ni\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e@Beta and Ni/Beta. (a)\u003c/strong\u003e H\u003csub\u003e2\u003c/sub\u003e-TPR profiles, and \u003cstrong\u003e(b)\u003c/strong\u003e Ni 2p XPS spectra of Ni/Beta and Ni\u003csub\u003e1\u003c/sub\u003e@Beta. Fourier transform infrared (FT-IR) spectra of CO adsorbed at low temperature (-170 \u003csup\u003eo\u003c/sup\u003eC) on \u003cstrong\u003e(c)\u003c/strong\u003e Ni\u003csub\u003e1\u003c/sub\u003e@Beta and \u003cstrong\u003e(d)\u003c/strong\u003e Ni/Beta.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-5796369/v1/a5824b911f1d658e4f2ca076.png"},{"id":73851631,"identity":"74aa1b82-1cda-4ae6-8026-1bdeddb7b60f","added_by":"auto","created_at":"2025-01-15 09:44:41","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2170870,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5796369/v1/3059cb32-7968-4ad8-8d54-3143112acd05.pdf"},{"id":73830280,"identity":"1bd26f56-168f-4871-b074-b548a315b36c","added_by":"auto","created_at":"2025-01-15 06:09:38","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":364189,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Scheme.docx","url":"https://assets-eu.researchsquare.com/files/rs-5796369/v1/1b47c8411384bf8ebca06e99.docx"},{"id":73830285,"identity":"8811227b-24a3-4604-98c8-03965c80bec5","added_by":"auto","created_at":"2025-01-15 06:09:38","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":4795934,"visible":true,"origin":"","legend":"\u003cp\u003eChelating-agent-free incorporation of isolated Ni single-atoms within BEA Zeolite for enhanced biomass hydrogenation\u003c/p\u003e","description":"","filename":"SupportingInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-5796369/v1/4dcd53ff060983082fc5bee7.docx"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Chelating-agent-free incorporation of isolated Ni single-atoms within BEA Zeolite for enhanced biomass hydrogenation","fulltext":[{"header":"Introduction","content":"\u003cp\u003eZeolites, with ordered microporous architectures, tunable functions and high specific surface area as well as excellent thermal stability, render them the catalytic workhorses of various reactions in chemical industries and refineries.\u003csup\u003e1,2\u003c/sup\u003e Additionally, zeolites have been shown to be versatile and powerful scaffolds for incorporating small metal entities in terms of nanoclusters or even isolated atoms, to generate efficient bifunctional catalysts.\u003csup\u003e3-5\u003c/sup\u003e Single-atom catalysts (SACs) have emerged as a new frontier in catalysis science and have attracted extensive attention because of the maximum atom efficiency and unique catalytic properties.\u003csup\u003e6-8\u003c/sup\u003e Zeolite incorporated metal single-atoms are the suitable candidates for high-activity catalysis, which not only capitalize on the advantages of ingenious atomic utilization and the resulting unique performance but also achieve an outstanding stability against sintering or leaching by the confinement effect of zeolites.\u003csup\u003e9-11\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eCommon methods for incorporating metal single-atoms within zeolites involve post-synthesis approaches (such as impregnation, ion exchange) or \u003cem\u003ein situ\u003c/em\u003e synthesis methods. Although atomically dispersed metal atoms can be introduced into zeolites by post-synthesis treatments, only low metal loading contents can be achieved (\u0026lt;0.2 wt %).\u003csup\u003e12-14\u003c/sup\u003e Moreover, due to the weak interaction between metal atoms and the zeolite framework, these isolated metal atoms could migrate to the surface and sinter into large particles during thermal treatment or under reaction conditions.\u003csup\u003e15\u003c/sup\u003e To this end, \u003cem\u003ein situ\u003c/em\u003e metal incorporation during the zeolite synthesis process is preferable and has more recently been employed for anchoring isolated atoms into zeolites.\u003csup\u003e16,17\u003c/sup\u003e Generally, such incorporation approaches are implemented by using a suitable chelating agent to inhibit metal precipitation or agglomeration during the zeolite synthesis. For example, Yu et al. reported an\u003cem\u003e\u0026nbsp;in situ\u0026nbsp;\u003c/em\u003ehydrothermal method for incorporating isolated Rh metal atoms inside pure-silica MFI zeolite by using ethylenediamine as a chelating ligand.\u003csup\u003e16\u003c/sup\u003e Similarly, Li et al. also incorporated isolated Pt cations into Y zeolite through an \u003cem\u003ein situ\u003c/em\u003e hydrothermal synthesis method, in which H\u003csub\u003e2\u003c/sub\u003ePtCl\u003csub\u003e6\u003c/sub\u003e was stabilized by 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane (TAPTS).\u003csup\u003e17\u003c/sup\u003e Obviously, these reported hydrothermal synthesis strategies for incorporating metal single-atoms within zeolites rely heavily on the usage of a suitable ligand that can coordinate with metal ion to avoid metal precipitation or hydrolysis during the synthetic process. However, the addition of chelating agents generally interrupts the assembly of a zeolite building units during crystallization process, and the strategy is limited within only a small number of zeolite synthesis systems. Additionally, most successful encapsulation is realized on noble metals with a high melting point (i.e., Pt and Rh), while non-noble metals are rarely reported because of their increased susceptibility to metal migration and agglomeration during the calcination and reduction process. Therefore, it is highly desirable to develop a facile, applicable synthesis method to incorporate non-noble metal single-atoms within zeolites.\u003c/p\u003e\n\u003cp\u003eIn this work, we report a simple and efficient \u003cem\u003ein situ\u003c/em\u003e two-step hydrothermal synthesis method to directly incorporate Ni single-atoms into the micropores of zeolite Beta without using chelating agent for stabilizing metal precursors. The proposed \u003cem\u003ein situ\u003c/em\u003e two-step hydrothermal method firstly generates crystal nuclei in nucleation process at a relatively low temperature, and then adds metal precursor to continue crystallization at high temperature.The nature of Ni single-atoms was confirmed by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM), X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy of CO adsorbed (FT-IR-CO). The density functional theory (DFT) calculations show that Ni single-atoms locate in 6-member ring (6-MR) of BEA zeolite and are stabilized by zeolite skeletal oxygens. Benefiting from the unique coordination environment of incorporated single Ni cations, the as-synthesized Ni\u003csub\u003e1\u003c/sub\u003e@Beta catalyst exhibits remarkable performance in the selective hydrogenation of biomass-derived furfural (FF) to furfuryl alcohol (FAL). This efficient synthesis approach for metal single-atoms incorporated within zeolite-based materials may open new perspectives for the rational design of catalysts for chemoselective reactions in biomass valorization and beyond.\u0026nbsp;\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e \u003cb\u003eSynthetic approach for incorporation of Ni single atoms.\u003c/b\u003e Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1\u003c/span\u003e illustrates the \u003cem\u003ein situ\u003c/em\u003e incorporation approach for the synthesis of the atomically dispersed Ni incorporated within Beta zeolite, namely Ni\u003csub\u003e1\u003c/sub\u003e@Beta. The metal incorporation is implemented by a two-step process, including the nucleation step of the alumino-silicate gel with a molar composition of SiO\u003csub\u003e2\u003c/sub\u003e/Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e/TEAOH/H\u003csub\u003e2\u003c/sub\u003eO/Na\u003csub\u003e2\u003c/sub\u003eO\u0026thinsp;=\u0026thinsp;1/0.014/0.19/7.21/0.042 at 100\u0026deg;C, and a subsequent zeolite crystallization with the introduction of nickel nitrate as the metal precursor at 140\u0026deg;C. The as-obtained zeolites were then washed, dried, calcinated and reduced to generate the target Ni\u003csub\u003e1\u003c/sub\u003e@Beta. For comparison, Ni/Beta was also prepared via wet impregnation of Beta with Ni(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e solution. Notably, Ni\u003csub\u003e1\u003c/sub\u003e@Beta shows a colour of white even after a reduction at 500\u0026deg;C, which is quite different from the dark colour of Ni/Beta (Supplementary Fig.\u0026nbsp;1), reflecting the unique configuration of Ni species in Ni\u003csub\u003e1\u003c/sub\u003e@Beta.\u003c/p\u003e \u003cp\u003eThe first step of the nucleation process is essential for the successful incorporation of Ni single-atoms within Beta zeolite. When \u003cem\u003ein situ\u003c/em\u003e one-step hydrothermal approach is applied for incorporating Ni metal into Beta zeolite, the high pH (\u0026gt;\u0026thinsp;12) favoring nucleation and crystallization of BEA zeolite could result in a rapid metal precipitation and further lead to a failure of metal incorporation (Supplementary Fig.\u0026nbsp;2a, 3). Iglesia et al. also confirmed many cationic precursors (e.g., Ru, Pt and Ag) precipitate as massive hydroxides in the alkaline media required for zeolite synthesis, resulting in the early formation of colloidal particles too large for encapsulation.\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e It is widely accepted that the direct incorporation of metal atoms during \u003cem\u003ein situ\u003c/em\u003e hydrothermal synthesis needs an addition of a chelating agent into the formula for avoiding the agglomeration of the metal precursor in a basic solution. The protocol has enabled the successful incorporation of Pt, Pd and Rh, Ir, Re, and Ag clusters within LTA, as well as Pt, Pd, Ru, and Rh clusters within GIS and SOD.\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e,\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e Notably, in the proposed \u003cem\u003ein situ\u003c/em\u003e two-step hydrothermal method, chelating agent was not used to stabilize Ni metal species, and the separating preliminary nucleation step can effectively avoid the formation of bulk Ni metal hydroxides and prevent the negative impact of the metal precursor on the zeolite self-assembly under the hydrothermal process (Supplementary Fig.\u0026nbsp;2, 3).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eCharacterization and validation of incorporation of isolated Ni single-atoms within BEA Zeolite.\u003c/b\u003e X-ray diffraction (XRD) spectroscopy was employed to determine the crystalline structure of synthesized Ni-containing zeolites. As shown in Supplementary Fig.\u0026nbsp;4, the diffraction peaks of Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta match well with the BEA zeolite (JCPDS no.: 47\u0026ndash;0183). Taking the crystallinity of synthesized Beta zeolite as 100%, the calculated crystallinity of Ni\u003csub\u003e1\u003c/sub\u003e@Beta decreases a little to 95% (Supplementary Table\u0026nbsp;1), indicating that the incorporation of nickel metal precursors did not interfere with the crystallization process. Importantly, no diffraction peaks corresponding to Ni or NiO are detected, demonstrating the high dispersion of Ni species in the as-synthesized zeolite samples. In addition, the Ni\u003csub\u003e1\u003c/sub\u003e@Beta exhibits a standard type I isotherm with a Brunauer-Emmett-Teller (BET) surface area of about 697 m\u003csup\u003e2\u003c/sup\u003e/g, indicating a microporous crystal structure (Supplementary Fig.\u0026nbsp;5, 6 and Supplementary Table\u0026nbsp;2). The Ni content of Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta is determined to be ~\u0026thinsp;1.1 wt % by inductively coupled plasma-optical emission spectroscopy (ICP-OES) (Supplementary Table\u0026nbsp;1).\u003c/p\u003e \u003cp\u003eAberration-corrected scanning transmission electron microscopy (AC-STEM) and the corresponding energy-dispersive X-ray (EDX) spectral mapping were further employed to study the metal dispersion in Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta. No Ni particles can be visible for the Ni\u003csub\u003e1\u003c/sub\u003e@Beta by AC-STEM in the bright-field images, reflecting the good dispersion of Ni species (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea, \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). Clearly, as displayed in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec, a lattice fringe spacing of ~\u0026thinsp;1.13 nm corresponds to \u003cem\u003ehkl\u003c/em\u003e (101) plane of Beta zeolite is observed in the high magnification STEM image of Ni\u003csub\u003e1\u003c/sub\u003e@Beta, again in line with the XRD results that the crystallinity of Beta zeolite is limitedly influenced by the Ni incorporation. High-angle annular dark-field (HAADF) STEM image of Ni\u003csub\u003e1\u003c/sub\u003e@Beta and elemental mappings further confirm the uniform distribution of Ni species through the whole Beta zeolite (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed). To gain the atomic resolution, AC-HAADF-STEM has been applied for Ni\u003csub\u003e1\u003c/sub\u003e@Beta, and atomically dispersed Ni species are clearly visualized as isolated bright dots in the AC-HAADF-STEM images (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ee, \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ef, highlighted by white circle). In contrast, Ni/Beta prepared via the conventional wet impregnation method shows an average Ni particle size of ~\u0026thinsp;7.6 nm, together with some large Ni nanoparticles observed on the surface of the Beta zeolite (Supplementary Fig.\u0026nbsp;7). The results of temperature-programmed desorption of hydrogen (H\u003csub\u003e2\u003c/sub\u003e-TPD) also confirm that the average size of Ni particles on Ni\u003csub\u003e1\u003c/sub\u003e@Beta are much smaller than that of Ni/Beta (Supplementary Fig.\u0026nbsp;8).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eX-ray absorption spectroscopy (XAS) was further employed to provide the chemical states and local coordination information of Ni species. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb show the X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra of Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta, and those of Ni foil and NiO as references. The detailed structural parameters obtained from EXAFS fittings are presented in Supplementary Table\u0026nbsp;2. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea, both Ni\u003csub\u003e1\u003c/sub\u003e@Beta and NiO share a comparable Ni valence state of +\u0026thinsp;2, and Ni/Beta shows a slightly lower valence state of Ni between 0 and +\u0026thinsp;2. In contrast, the XANES spectrum of Ni/Beta is much similar to Ni foil, but the white line intensity is higher, indicating that Ni species possess a higher valence state than the Ni foil due to the presence of small Ni particles,\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e,\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e which is consistent with the results of XPS. The first pre-edge peak at 8333 eV could be attributed to the 1s\u0026rarr;3d electronic transition of Ni cations in an octahedral symmetry,\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e which is normally forbidden due to orbital symmetry mismatch.\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e Only slight (p-d) orbital mixing in distorted local symmetry can provide some probability for the 1s\u0026rarr;3d transitions. Additionally, the second pre-edge peak at 8339 eV is attributed to the 1s\u0026rarr;4p\u003csub\u003ez\u003c/sub\u003e electronic transition, which often corresponds to the fingerprint of a square-planar Ni-O\u003csub\u003e4\u003c/sub\u003e structure.\u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e The pre-edge peaks of Ni\u003csub\u003e1\u003c/sub\u003e@Beta show markedly weakened intensity both at 8333 and 8339 eV, indicating a significant distorted Ni-O\u003csub\u003e4\u003c/sub\u003e geometry, rather than a square-planar structure. Combined with theoretical calculation, we propose a structure of Ni single atoms locate in a distorted tetrahedral coordination geometry. In the EXAFS spectrum of Ni\u003csub\u003e1\u003c/sub\u003e@Beta, significant peaks are detected at 1.63 and 2.76 \u0026Aring; (without phase correction), which could be identified as first shell Ni-O and second shell Ni-O-Si(Al) scattering paths, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). No obvious Ni-Ni peak and Ni-O-Ni peak can be visualized in Ni\u003csub\u003e1\u003c/sub\u003e@Beta, demonstrating that the Ni species exist as isolated single atoms. According to EXAFS fitting results (Supplementary Fig.\u0026nbsp;9, 10) and quantitative structure parameters (Supplementary Table\u0026nbsp;3), Ni-O coordination number (CN) is ~\u0026thinsp;4.0, indicating the isolated Ni species stabilized by four oxygen atoms in Beta zeolite framework. This model also matches well to the theoretically predicted structure that the Ni atom is coordinated with four O atoms, forming a distorted quasi-planar Ni-O\u003csub\u003e4\u003c/sub\u003e structure (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ed). For Ni/Beta, based on the EXAFS fitting results, the peaks at 2.03 \u0026Aring; with a CN of ~\u0026thinsp;2.1 and at 2.50 \u0026Aring; with a CN of ~\u0026thinsp;7.3 corresponding to Ni-O and Ni-Ni metallic, respectively. It indicates that some large Ni nanoparticles are formed on the Ni/Beta, which is in accordance with the observation of TEM measurements. In addition, the wavelet-transformed (WT) EXAFS counter plots of Ni\u003csub\u003e1\u003c/sub\u003e@Beta directly show the absence of Ni-Ni metallic bonds (Supplementary Fig.\u0026nbsp;11). Together, all the above results demonstrate that the Ni species in Ni\u003csub\u003e1\u003c/sub\u003e@Beta are atomically distributed and stabilized by four oxygen atoms in Beta zeolite framework, while the Ni species in Ni/Beta are mostly agglomerated into metallic Ni nanoparticles.\u003c/p\u003e \u003cp\u003eThe proposed structure of cationic Ni(II) incorporated in BEA zeolite was further investigated by DFT calculations. There are nine inequivalent T sites exist in BEA zeolite, and were labelled according to the zeolite structures database (Supplementary Fig.\u0026nbsp;12).\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e We first compared the energetics of Ni locate at 4-, 5- and 6-MR and found that Ni prefers to be in the 6-MR ring of BEA zeolite (Supplementary Fig.\u0026nbsp;13). Three 6-MRs have highly similar Ni(II)-bound sites and ring A1 is described here (Supplementary Fig.\u0026nbsp;14 and Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec). The 6-MR with two aluminium T-sites (anionic AlO\u003csub\u003e4\u003c/sub\u003e tetrahedra) shows that for BEAs with a Si/Al ratio greater than 10, there are three possible configurations for these aluminium T-sites (Si/Al ratios greater than 25 are used here).\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e We further evaluate the effect of aluminium configuration on the resulting Ni(II)-bound site (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ed), including T4/T4\u0026rsquo; and T8/T8\u0026rsquo;, which bind Ni(II) with two neutral \u003csub\u003eSi\u003c/sub\u003eO\u003csub\u003eSi\u003c/sub\u003e ligands and two anionic \u003csub\u003eSi\u003c/sub\u003eO\u003csub\u003eAl\u003c/sub\u003e ligands, and T6/T6\u0026rsquo;, which binds Ni(II) with four anionic \u003csub\u003eSi\u003c/sub\u003eO\u003csub\u003eAl\u003c/sub\u003e ligands. T6/T6\u0026rsquo; binds Ni(II) with four anionic \u003csub\u003eSi\u003c/sub\u003eO\u003csub\u003eAl\u003c/sub\u003e ligands is the most stable configuration (Supplementary Table\u0026nbsp;4). Notably, the Ni sites are accessible from 12-MRs of Beta zeolite (Supplementary Fig.\u0026nbsp;12), which is beneficial for the catalytic interaction between Ni active sites and reaction substrates. In addition, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee, the bond lengths of the Ni atom with the surrounding O atoms are 1.91, 2.05, 1.91 and 2.04 \u0026Aring;, respectively, which are consistent with EXAFS fitting results. Moreover, the charge density difference of Ni\u003csub\u003e1\u003c/sub\u003e@Beta shows remarkable electron transfer from Ni atom to the first coordinated O atoms due to the formation of Ni-O band (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ef and Supplementary Table\u0026nbsp;5). The isosurface map of interaction region indicator (IRI) performed using the Multiwfn 3.8 (dev) code\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e further reveals that the isolated Ni sites are stabled through bonding to oxygen atoms in the framework of Beta zeolite (Supplementary Fig.\u0026nbsp;15).\u003c/p\u003e \u003cp\u003eIn brief, we have successfully prepared isolated Ni species incorporated into the Beta zeolite. All characterizations validate that isolated, distorted tetrahedral Ni species are situated in the center of 6-MRs of zeolite Beta and stabilized by four framework oxygen atoms. Benefiting from the good dispersion of Ni atoms, the unique structure of a coordination environment, and the specific electronic configuration of Ni species, Ni\u003csub\u003e1\u003c/sub\u003e@Beta, upholding the isolated Ni sites combined with the specific zeolite microenvironment, could afford a unique performance in selective hydrogenation reactions.\u003csup\u003e\u003cspan additionalcitationids=\"CR30\" citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eCatalyst performance and stability.\u003c/b\u003e The catalytic hydrogenation of FF into FAL is one of the important reactions to convert biomass-derived compounds into value-added chemicals and fuels.\u003csup\u003e\u003cspan additionalcitationids=\"CR33 CR34\" citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e Heterogeneous non-noble Ni-based catalysts have shown good FF hydrogenation ability, but the major challenge comes from the over-hydrogenation of FAL, often leading to a low FAL selectivity.\u003csup\u003e\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e,\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e The selective hydrogenation of FF into FAL was performed under batch conditions with isopropanol as the solvent to evaluate the catalytic performance of Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta (Supplementary Table\u0026nbsp;6 and Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). FAL, tetrahydrofurfuryl alcohol (THFA), furfural diisopropyl acetal (FDA), and furfuryl isopropyl ether (FIE) are observed as the main products. The support of Beta possesses limited activity, with an FF conversion of 5.2% after 1 h (Supplementary Table\u0026nbsp;6, entry 1). After the Ni supported by the wet impregnation method, the as-obtained Ni/Beta catalyst affords an FF conversion of 57.6% and a FAL yield of 41.5% after 1 h, with a turnover frequency (TOF) of 37.6 h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, calculated as the converted number of FF (mol) per Ni site (mol) per unit time (h) at a low conversion level of 20.8% (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb and Supplementary Table\u0026nbsp;6, entry 7). Comparatively, the Ni\u003csub\u003e1\u003c/sub\u003e@Beta prepared by the \u003cem\u003ein situ\u003c/em\u003e two-step hydrothermal strategy displays a marked increase in activity than the Ni/Beta, with an FF conversion of 93.7% and a FAL yield of 85.8%, referring to a TOF of 114.1 h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb and Supplementary Table\u0026nbsp;6, entry 8), which is much higher than the state-of-the-art Ni-based heterogeneous catalysts under similar reaction conditions (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec and Supplementary Table\u0026nbsp;7).\u003csup\u003e\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e,\u003cspan additionalcitationids=\"CR39 CR40 CR41 CR42 CR43\" citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u003c/sup\u003e To the best of our knowledge, such high activity and FAL yield are rarely observed for a supported Ni catalyst. SACs with the high atom utilization, as well as a unique configuration has provided an enhanced performance. Moreover, a larger amount of spillovered hydrogen (529\u0026deg;C, Supplementary Fig.\u0026nbsp;8) could be determined for Ni\u003csub\u003e1\u003c/sub\u003e@Beta than for Ni/Beta, implying the atomically dispersed Ni cations within Ni\u003csub\u003e1\u003c/sub\u003e@Beta could improve hydrogenation performance markedly by facilitating the spillover of active hydrogen.\u003csup\u003e\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e,\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u003c/sup\u003e As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb, when increasing the reaction time to 2 h, Ni\u003csub\u003e1\u003c/sub\u003e@Beta shows a full conversion of FF, with a FAL yield of 88.2% and a THFA yield of 5.6%. As for Ni/Beta, the FF conversion increases to 87.1%, with a FAL yield of 53.0% and a THFA yield of 25.3%. These results indicate that the hydrogenation of FAL to THFA can be effectively suppressed for Ni\u003csub\u003e1\u003c/sub\u003e@Beta owing to the efficient modulation of Ni species in zeolite micro-environment. In order to further confirm the specificity of zeolite structure, we synthesized Ni particles supported on an open-structure support (Ni/SiO\u003csub\u003e2\u003c/sub\u003e, Supplementary Table\u0026nbsp;6, entry 6), which exhibits a good capacity of over-hydrogenation, with a THFA selectivity of 22.0%, which is much higher than Ni/Beta (9.6%) and Ni\u003csub\u003e1\u003c/sub\u003e@Beta (2.5%) at a comparable low FF conversion of ~\u0026thinsp;20.0%. The main reason could be attributed to the lack of constrained environments and proper modulation of electronic configuration for Ni species, resulting in the loss in FAL selectivity owing to consecutive hydrogenation of FAL into THFA.\u003c/p\u003e \u003cp\u003eThe stability of Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta is further examined by performing consecutive runs in the selective hydrogenation of FF into FAL. Ni\u003csub\u003e1\u003c/sub\u003e@Beta or Ni/Beta after the reaction was filtered, washed with isopropanol and dried at 60\u0026deg;C overnight. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed, Ni\u003csub\u003e1\u003c/sub\u003e@Beta shows no apparent decrease in the FF conversion, from an initial 70.7 to 68.7% upon five consecutive runs. The yield of FAL is well-maintained at a similar level of 64\u0026ndash;67% upon catalysis. No notable changes in activity and selectivity confirm no apparent deactivation, indicating the excellent stability of Ni\u003csub\u003e1\u003c/sub\u003e@Beta. In contrast, an obvious deactivation is observed with Ni/Beta, with a distinct drop in FF conversion from 68.7\u0026ndash;10.2% and the FAL yield from 52.8\u0026ndash;7.6% through five consecutive runs (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ee). To track the possible changes of the catalysts, XRD, ICP-OES, and STEM were conducted for the spent Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta. After five consecutive runs, XRD results reveal that both Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta retain the BEA zeolite structure integrity during recycling tests (Supplementary Fig.\u0026nbsp;16). ICP-OES shows a decrease in Ni content from 1.10 to 0.74 wt % for the spent Ni/Beta (Supplementary Table\u0026nbsp;1). Moreover, the mean size of Ni nanoparticles in Ni/Beta increases from ~\u0026thinsp;7.6 to ~\u0026thinsp;12.4 nm after five consecutive runs (Supplementary Fig.\u0026nbsp;17a, b). These results suggest that the deactivation of Ni/Beta may be due to the combined effects of Ni leaching and aggregation. Conversely, no metal leaching is detected for the spent Ni\u003csub\u003e1\u003c/sub\u003e@Beta (Supplementary Table\u0026nbsp;1). In addition, STEM image shows no observable agglomeration of metal species for the spent Ni\u003csub\u003e1\u003c/sub\u003e@Beta, and AC-HAADF-STEM images of the spent Ni\u003csub\u003e1\u003c/sub\u003e@Beta further reveals that Ni species maintain as isolated Ni atoms (Supplementary Fig.\u0026nbsp;17c, d), corroborating again the excellent stability of Ni\u003csub\u003e1\u003c/sub\u003e@Beta in the selective hydrogenation of FF.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eInsights into catalytic behavior.\u003c/b\u003e The remarkable catalytic performance of Ni\u003csub\u003e1\u003c/sub\u003e@Beta closely related to the electronic properties of isolated Ni sites. H\u003csub\u003e2\u003c/sub\u003e temperature-programmed reduction (H\u003csub\u003e2\u003c/sub\u003e-TPR) was performed for Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea). For Ni/Beta, a broad H\u003csub\u003e2\u003c/sub\u003e-consumption peak at around 464\u0026deg;C can be assigned to the reduction of NiO to metallic Ni.\u003csup\u003e\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e,\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u003c/sup\u003e For Ni\u003csub\u003e1\u003c/sub\u003e@Beta, a signal at a higher temperature of 650\u0026deg;C, can be attributed to the reduction of isolated Ni cations located in the zeolite pores, indicating a stronger metal-support interaction in Ni\u003csub\u003e1\u003c/sub\u003e@Beta than that in Ni/Beta.\u003csup\u003e49,50\u003c/sup\u003e The XPS analyses were further used to characterize the electronic states of Ni species in Ni/Beta and Ni\u003csub\u003e1\u003c/sub\u003e@Beta. Prior to the XPS measurement, both samples were sputtered with Ar\u003csup\u003e+\u003c/sup\u003e ion for two minutes to etch the surface oxide layer. The XPS spectrum of the Ni 2p\u003csub\u003e3/2\u003c/sub\u003e for Ni\u003csub\u003e1\u003c/sub\u003e@Beta catalyst (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb) only shows one characteristic peak at 856.1 eV, which is attributed to the Ni\u003csup\u003e2+\u003c/sup\u003e species.\u003csup\u003e\u003cb\u003e错误!未找到引用源。\u003c/b\u003e\u003c/sup\u003e This again in line with XAS results that the Ni species of Ni\u003csub\u003e1\u003c/sub\u003e@Beta bear the positive charge. As for Ni/Beta, two main peaks center at 852.5 and 855.8 eV are observed in Ni 2p\u003csub\u003e3/2\u003c/sub\u003e signal, corresponding to Ni\u003csup\u003e0\u003c/sup\u003e and Ni\u003csup\u003e2+\u003c/sup\u003e species, respectively.\u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e,\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u003c/sup\u003e Notably, the peak of Ni\u003csup\u003e2+\u003c/sup\u003e in Ni\u003csub\u003e1\u003c/sub\u003e@Beta is shifted to a slightly higher binding energy compared to Ni/Beta. This positive shift indicates a buidup of positive charges on the Ni species, which also points to an enhanced electron interaction between Ni and O atoms (Supplementary Fig.\u0026nbsp;18). Recently, Li and co-workers have demonstrated that the electron-rich Pd single-atom sites would promote the dissociation of H\u003csub\u003e2\u003c/sub\u003e and the adsorption of substrate on Pd sites, which afforded enhanced performance in the semi-hydrogenation of a broad range of substrates.\u003csup\u003e\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTo further characterize the electronic configuration of Ni species in Ni/Beta and Ni\u003csub\u003e1\u003c/sub\u003e@Beta, FT-IR-CO was performed at a low temperature of -170\u0026deg;C with stepwise adsorption of CO (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ed). As shown in Supplementary Fig.\u0026nbsp;19, the vibrational features of adsorbed-CO at around 2170 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 2129 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e over Beta zeolite, are associated with carbonyls formed with the participation of Na\u003csup\u003e+\u003c/sup\u003e ions.\u003csup\u003e54\u0026ndash;56\u003c/sup\u003e For the Ni\u003csub\u003e1\u003c/sub\u003e@Beta (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec), in addition to the CO adsorption on Na\u003csup\u003e+\u003c/sup\u003e, a new peak appears at 2202 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, which can be assigned to adsorption of CO on isolated Ni\u003csup\u003e2+\u003c/sup\u003e sites according to previous reports.\u003csup\u003e\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e,\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e\u003c/sup\u003e In the case of Ni/Beta (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ed), the adsorption of CO on Ni produces two additional bands centred at ~\u0026thinsp;2020 and ~\u0026thinsp;1900 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, besides the CO signals observed for Ni\u003csub\u003e1\u003c/sub\u003e@Beta. The former is attributed to linear-adsorbed CO on metallic Ni nanoparticles and the latter is ascribes to bridging Ni-CO species.\u003csup\u003e\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e,\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e Notably, such two signals were not apparent for Ni\u003csub\u003e1\u003c/sub\u003e@Beta, further confirming that the Ni species in Ni\u003csub\u003e1\u003c/sub\u003e@Beta are atomically dispersed. In addition, as for Ni/Beta, there also exits a smaller peak at 2202 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, indicating the presence of Ni\u003csup\u003e2+\u003c/sup\u003e species in Ni/Beta, consistent with the XPS results.\u003c/p\u003e \u003cp\u003eBase on the above results, the excellent catalytic performance of Ni\u003csub\u003e1\u003c/sub\u003e@Beta in the selective hydrogenation of FF into FAL is not only related to the successful incorporation of Ni single-atoms but also to the appropriate modulation of the coordination environment of Ni atoms by the restricted zeolite micro-environment. Zeolite-tailored metal incorporation can efficiently restrict the migration of isolated Ni species by spatial restriction of the confined micro-environment, preventing metal sintering and leaching efficiently during catalysis. Besides, the confined environment of the zeolite could also induce the formation of a unique coordinated spatial structure (Ni-O\u003csub\u003e4\u003c/sub\u003e sites), which efficient modulate the electronic configuration of the isolated Ni species (bear a positive charge of ~\u0026thinsp;Ni\u003csup\u003e2+\u003c/sup\u003e) and exhibit specific adsorption and desorption to FF and FAL, facilitating hydrogen spillover and thus enhancing performance in the selective hydrogenation of FF into FAL.\u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e,\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e,\u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn summary, a facile \u003cem\u003ein situ\u003c/em\u003e hydrothermal synthesis strategy is developed for precisely incorporating isolated Ni species into Beta zeolite without using any chelating agent for stabilizing Ni metals for the first time. AC-HAADF-STEM and XAS analyses, combined with DFT calculations, reveal the fine structure of the as-prepared Ni\u003csub\u003e1\u003c/sub\u003e@Beta, where the atomically dispersed Ni\u003csup\u003e2+\u003c/sup\u003e species are stabilized by the surrounding four oxygen atoms in six-membered rings. Benefiting from unique coordination environment and maximum atomic utilization of incorporated Ni single-atoms within Beta zeolite, the as-obtained Ni\u003csub\u003e1\u003c/sub\u003e@Beta catalyst exhibits excellent catalytic activity and selectivity in the selective hydrogenation of FF into FAL, with a TOF value up to 114.1 h\u003csup\u003e-1\u003c/sup\u003e, surpassing that of Ni/Beta prepared by impregnation method and those of previously reported Ni-based heterogeneous catalysts. Additionally, this confinement structure and coronation environment significantly improve the stability and sintering resistance of Ni\u003csub\u003e1\u003c/sub\u003e@ Beta. These findings afford an efficient strategy for the efficientfabrication of isolated non-noble metal atoms within zeolite structure, which will be of great aid and potential for the rational design of active and selective zeolitic materials for hydrogen-assisted biomass valorization and other energy-related reactions.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eMaterials for catalyst synthesis.\u0026nbsp;\u003c/strong\u003eTetraethylammonium hydroxide (TEAOH, 25 wt% in H\u003csub\u003e2\u003c/sub\u003eO), silica gel (99\u0026nbsp;wt% SiO\u003csub\u003e2\u003c/sub\u003e,), furfural (99%) and isopropanol (99%) were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. Sodium hydroxide (NaOH, 99%) was obtained from Sinopharm Chemical Reagent Co., Ltd. Sodium metaaluminate (NaAlO\u003csub\u003e2\u003c/sub\u003e, 45 wt% Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e) was obtained from Tianjin Jinke Fine Chemical Research Institute. Nickel (II) nitrate hexahydrate (Ni(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e·6H\u003csub\u003e2\u003c/sub\u003eO, 98%) was obtained from Tianjin Fuchen Chemical Reagent Factory. Above materials were used without further purification.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of Beta zeolite\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003evia\u003c/strong\u003e \u003cstrong\u003ea hydrothermal method.\u003c/strong\u003e In a typical process, 27.9 g TEAOH and 0.45 g NaOH were added to 11.48 g deionized water, and stirred until a clear solution was formed. Subsequently, 0.8 g NaAlO\u003csub\u003e2\u003c/sub\u003e was added and stirring was continued for 30 min. Then, 15 g silica gel was slowly added to the above solution and stirred for 3 h to a resulting alumino-silicate gel. The resulting gel was transferred into a 100 mL Teflon lining stainless-steel autoclave, placed in an oven at 140 °C and crystallized for 48 h. After crystallization, the autoclave was quenched with flowing water, and the solid products were separated by centrifuge, and washed with deionized water until the pH value of filtrate was ~ 7. After that, the solid product was transferred to a 100 °C oven and dried for 12 h. Finally, the Beta zeolite was obtained by calcination in the air at 550 °C for 6 h (heating rate: 2 °C min\u003csup\u003e-1\u003c/sup\u003e).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of Ni\u003csub\u003e1\u003c/sub\u003e@Beta via an \u003cem\u003ein situ\u003c/em\u003e two-step hydrothermal method\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e The alumino-silicate gel with the same makeup as of Beta zeolite was placed in an autoclave at 100 °C for 24 h, and then the autoclave was cooled to ambient temperature. Next, 0.75 g Ni(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e precursor dissolved into 1 g deionized water was introduced into the contents of the autoclave. The autoclave was sealed again, heated to 140 °C and kept at this temperature for 36 h. The as obtained solid product was filtered, washed with water for several times, and then dried at 100 °C in the oven overnight, followed by calcination at 550 °C for 6 h. Finally, reduced at 30 mL min\u003csup\u003e-1\u003c/sup\u003e 10% H\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eflow at 500 °C (heating rate: 5 °C min\u003csup\u003e-1\u003c/sup\u003e) for 2 h. Before exposure to air, all the samples were passivated at 30 °C for 1 h under 30 mL min\u003csup\u003e-1\u003c/sup\u003e 1% O\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e flow.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of Ni/Beta-HT via an \u003cem\u003ein situ\u003c/em\u003e one-step hydrothermal method.\u003c/strong\u003e Ni/Beta-HT was prepared using the same alumino-silicate gel composition with Ni(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e precursor of Ni\u003csub\u003e1\u003c/sub\u003e@Beta above. In a typical synthesis, the obtained gel was prepared and directly put in a 140 °C oven for hydrothermal synthesis for 48 h without the first step of the nucleation process. The solid product was filtered, washed with H\u003csub\u003e2\u003c/sub\u003eO for several times, and dried in an oven at 100 °C overnight, and calcined at 550 °C for 6 h. Finally, the sample was reduced at 500°C for 2 h and passivated at 30 °C for 1 h.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of Ni/Beta and Ni/SiO\u003csub\u003e2\u003c/sub\u003e via impregnation method.\u003c/strong\u003e Ni/Beta and Ni/SiO\u003csub\u003e2\u003c/sub\u003e were prepared by wet impregnation method with Ni(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e solution. The samples were dried at 100 °C overnight. Followed by calcination, reduction and passivation, the steps are the same as Ni\u003csub\u003e1\u003c/sub\u003e@Beta.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCatalyst evaluation.\u0026nbsp;\u003c/strong\u003eThe hydrogenation of furfural in a liquid-phase was carried out in a 100 mL autoclave. In a typical procedure, 0.3 g furfural was mixed with 23.56 g isopropanol, and then 0.3 g catalyst was added. The reactor was sealed, and then purged with N\u003csub\u003e2\u003c/sub\u003e and H\u003csub\u003e2\u003c/sub\u003e for three times, repectively. Next, the autoclave was pressurized with H\u003csub\u003e2\u003c/sub\u003e and subsequently heated to the reaction temperature. After reaction, the autoclave was rapidly cooled and the products were collected using a 0.22 μm filter membrane and analyzed by Agilent GC 7890B (HP-5 column) with N,N-Dimethylformamide (DMF) as an internal standard. The reusability test of Ni\u003csub\u003e1\u003c/sub\u003e@Beta and Ni/Beta catalyst was investigated under the furfural conversion at ~ 70%; the catalysts after each reaction were separated by centrifugation, washing with isopropanol and dried at 60 °C for 12 h.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCatalyst characterization.\u0026nbsp;\u003c/strong\u003eX-ray diffraction (XRD) detection was conducted using a Bruker D8 Advance diffractometer with Cu-Kα radiation source (40 kV, 40 mA).\u003c/p\u003e\n\u003cp\u003eThe Si/Al molar ratio of zeolite samples were determined by the X-ray fluorescence (XRF), which was conducted on a PANalytical AxiosMAX analyzer. The inductively coupled plasma-optical emission spectroscopy (ICP-OES) was performed on a PerkinElmer Optima 7300V to obtain chemical compositions of zeolite samples.\u003c/p\u003e\n\u003cp\u003eThe scanning electron microscopy (STEM) images was recorded on a Gemini SEM 300 field-emission microscope.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe texture properties of zeolite samples were recorded using a Kubo X1000 setup operating at -196 °C. Before sorption measurements, samples were treated at 350 °C for 4 h under vacuum to eliminate adsorbed substances.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe aberration-corrected scanning transmission electron microscopy (AC-STEM) images performed on on a JEOL JEM-ARM200F with a CEOS probe corrector at 200 kV. For the high-angle annular dark-field (HAADF) imaging, identical convergence and collection angle ranges were implemented. Energy dispersive X-ray spectra (EDX-mapping) were collected with a JEOL Oxford X-MaxN 80 T silicon drift detector.\u003c/p\u003e\n\u003cp\u003eThe temperature-programmed desorption of hydrogen (H\u003csub\u003e2\u003c/sub\u003e-TPD) and H\u003csub\u003e2\u003c/sub\u003e temperature-programmed reduction (H\u003csub\u003e2\u003c/sub\u003e-TPR) were conducted on a chemisorption instrument (Huasi DAS-7000), which equipped with a TCD detector. For H\u003csub\u003e2\u003c/sub\u003e-TPD, about 100 mg zeolite samples were firstly treated in the N\u003csub\u003e2\u003c/sub\u003e flow (30 ml min\u003csup\u003e-1\u003c/sup\u003e) at 400 °C for 1 h, and then cooled down to room temperature. Next, the zeolite samples were saturated with 10% H\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e flow (30 mL min\u003csup\u003e-1\u003c/sup\u003e) and then purged with N\u003csub\u003e2\u003c/sub\u003e to eliminated the weakly adsorbed species. Finally, the H\u003csub\u003e2\u003c/sub\u003e-TPD profile was recorded from 30 °C to 800 °C (5 °C min\u003csup\u003e-1\u003c/sup\u003e).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFor H\u003csub\u003e2\u003c/sub\u003e-TPR experiments, about 50 mg unreduced zeolite samples were dehydrated at 400 °C for 1 h and cooled down to 50 °C in flowing N\u003csub\u003e2\u003c/sub\u003e (30 mL min\u003csup\u003e-1\u003c/sup\u003e). Then the H\u003csub\u003e2\u003c/sub\u003e-TPR spectra were recorded in the 10 % H\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e (30 mL min\u003csup\u003e-1\u003c/sup\u003e) flow by increasing reduction temperature from 50 °C to 800 °C (5 °C min\u003csup\u003e-1\u003c/sup\u003e).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eX-ray absorption spectroscopy (XAS), encompassing X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy at the Ni K-edge, were obtain on Beijing Synchrotron Radiation Facility (BSRF) with 1W1B beamlines at 250 mA. The spectra were recorded in fluorescence mode on a self-supported wafer at ambient temperature. The Ni foil was utilized for the calibration of energy. The XAFS datas were further analyzed using Athena and Artemis modules, which equipped with the IFEFFIT software package.\u003c/p\u003e\n\u003cp\u003eAll calculations are implemented using the GGA-PBE electronic exchange-related functions from the Vienna ab initio simulation package (VASP 5.4.4). The cutoff energy was fixed at 400 eV. The Brillouin zone was sampled using 1×1×1 gamma points. The force was kept below 0.05 eV Å\u003csup\u003e-1\u003c/sup\u003e in the optimization of all structures. As for the analysis and calculation of IRI maps, Multiwfn 3.8 (dev) software was used.\u003c/p\u003e\n\u003cp\u003eX-ray photoelectron spectra (XPS) were conducted at a Thermo Scientific K-Alpha apparatus using Al Kα radiation. Before detection, the sample were etched by Ar\u003csup\u003e+\u003c/sup\u003e ions of 2 min. Binding energies (BE) were calibrated by adjusting the BE of the C1s peak to 284.8 eV.\u003c/p\u003e\n\u003cp\u003eFourier transform infrared (FT-IR) spectra after CO adsorption were recorded with a Bruker Tensor II instrument. Before spectral acquisition, samples were pressed into self-supported wafers and placed inside the self-designed cell, then treated at 350 °C for 1 h in N\u003csub\u003e2\u003c/sub\u003e flow, and continuously reduced at H\u003csub\u003e2\u003c/sub\u003e flow for 1 h. Subsequently, the temperature of the IR cell was cooled to 30 °C with circulating water and evacuated to 10\u003csup\u003e-8\u003c/sup\u003e bar. The IR cell was then continued to cool to -170 °C with liquid N\u003csub\u003e2\u003c/sub\u003e and the spectrum was recorded at this point as a background signal. CO adsorption was studied at -170 °C by gradually increasing the pressure (from 0 to 2.0 mbar).\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work is supported by the National Key Research and Development Program of China (2022YFB3805602), CNPC Innovation Found (2021DQ02-0702), National Natural Science Foundation of China (22078316 and 22479082), the funding of Inner Mongolia University (10000-23112101/081) and the funding of Inner Mongolia Youth Science and Technology Talents (NJYT24019).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eM.L. conducted the catalyst preparation, activity tests and most of catalyst characterizations. C.M., Y.N. and Y.Z. conducted and analysed FT-IR-CO experiments.\u0026nbsp;Y.F.\u0026nbsp;and\u0026nbsp;W.S.\u0026nbsp;performed the DFT calculations. W.W. and J.L. collected the high-resolution STEM measurements. S.C. performed XAS experiments. Z.W. and W.L. conceived the ideas and designed the project. M.L., Z.W. and W.L. wrote the paper with collective contributions and discussion from all authors. All authors approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting financial interests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing financial interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAdditional information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupplementary information\u003c/strong\u003e is available in the online version of the paper.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrespondence and requests for materials\u003c/strong\u003e should be addressed to Z.W. or W.L.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eReprints and permissions information\u003c/strong\u003e is available online at www.nature.com/reprints.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePublisher\u0026rsquo;s note\u003c/strong\u003e Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eZhang, Q., Gao, S. \u0026amp; Yu, J. Metal Sites in Zeolites: Synthesis, characterization, and catalysis. \u003cem\u003eChem. Rev\u003c/em\u003e. \u003cstrong\u003e123\u003c/strong\u003e, 6039-6106 (2022).\u003c/li\u003e\n\u003cli\u003eWu, Q., Xu, C., Zhu, L., Meng, X. \u0026amp; Xiao, F.-S. Recent strategies for synthesis of metallosilicate zeolites. \u003cem\u003eCatal. Today\u003c/em\u003e \u003cstrong\u003e390-391\u003c/strong\u003e, 2-11 (2022).\u003c/li\u003e\n\u003cli\u003eYang, J.\u003cem\u003e et al.\u003c/em\u003e Enhanced catalytic performance through in situ encapsulation of ultrafine Ru clusters within a high-aluminum zeolite. \u003cem\u003eACS Catal.\u003c/em\u003e \u003cstrong\u003e12\u003c/strong\u003e, 1847-1856, (2022).\u003c/li\u003e\n\u003cli\u003eCao, P.\u003cem\u003e et al.\u003c/em\u003e Zeolite-encapsulated Cu nanoparticles for the selective hydrogenation of furfural to furfuryl alcohol. \u003cem\u003eACS Catal.\u003c/em\u003e \u003cstrong\u003e11\u003c/strong\u003e, 10246-10256, (2021).\u003c/li\u003e\n\u003cli\u003eMa, B.\u003cem\u003e et al.\u003c/em\u003e Implanting colloidal nanoparticles into single-crystalline zeolites for catalytic dehydration. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e63\u003c/strong\u003e, e202403245 (2024).\u003c/li\u003e\n\u003cli\u003eLu, Y. B., Zhang, Z. H., Wang, H. M. \u0026amp; Wang, Y. Toward efficient single-atom catalysts for renewable fuels and chemicals production from biomass and CO. \u003cem\u003eAppl Catal B-Environ.\u003c/em\u003e \u003cstrong\u003e292\u003c/strong\u003e, 120162-120199 (2021).\u003c/li\u003e\n\u003cli\u003eLiang, X., Fu, N. H., Yao, S. C., Li, Z. \u0026amp; Li, Y. D. The progress and outlook of metal single-atom-site catalysis. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e144\u003c/strong\u003e, 18155-18174 (2022).\u003c/li\u003e\n\u003cli\u003eJing, W.\u003cem\u003e et al.\u003c/em\u003e Surface and interface coordination chemistry learned from model heterogeneous metal nanocatalysts: From atomically dispersed catalysts to atomically precise clusters. \u003cem\u003eChem. Rev\u003c/em\u003e, 1\u003cstrong\u003e23\u003c/strong\u003e, 5948-6002 (2023).\u003c/li\u003e\n\u003cli\u003eCheng, Q.\u003cem\u003e et al.\u003c/em\u003e Highly efficient and stable methane dry reforming enabled by a single-site cationic Ni catalyst. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e145\u003c/strong\u003e, 25109-25119 (2023).\u003c/li\u003e\n\u003cli\u003eYu, Z.\u003cem\u003e et al.\u003c/em\u003e Suppressing metal meaching and sintering in hydroformylation reaction by modulating the coordination of Rh single atoms with reactants. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e146\u003c/strong\u003e, 11955-11967 (2024).\u003c/li\u003e\n\u003cli\u003eChai, Y. C.\u003cem\u003e et al.\u003c/em\u003e Control of zeolite pore interior for chemoselective alkyne/olefin separations. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e368\u003c/strong\u003e, 1002-1006 (2020).\u003c/li\u003e\n\u003cli\u003eLiu, M., Miao, C. \u0026amp; Wu, Z. Recent advances in the synthesis, characterization, and catalytic consequence of metal species confined within zeolite for hydrogen-related reactions. \u003cem\u003eInd. Chem. \u0026amp; Mater.\u003c/em\u003e \u003cstrong\u003e2\u003c/strong\u003e, 57-84 (2024).\u003c/li\u003e\n\u003cli\u003eHuang, W. X.\u003cem\u003e et al.\u003c/em\u003e Low-temperature transformation of methane to methanol on PdO single sites anchored on the internal surface of microporous silicate. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e55\u003c/strong\u003e, 13441-13445 (2016).\u003c/li\u003e\n\u003cli\u003eXu, K.\u003cem\u003e et al.\u003c/em\u003e Partial hydrogenation of anisole to cyclohexanone in water medium catalyzed by atomically dispersed Pd anchored in the micropores of zeolite. \u003cem\u003eAppl. Catal. B: Environ.\u003c/em\u003e \u003cstrong\u003e341\u003c/strong\u003e, 123244-123254 (2024).\u003c/li\u003e\n\u003cli\u003eZecevic, J., van der Eerden, A. M. J., Friedrich, H., de Jongh, P. E. \u0026amp; de Jong, K. P. Heterogeneities of the nanostructure of platinum/zeolite Y catalysts revealed by electron tomography. \u003cem\u003eACS Nano\u003c/em\u003e \u003cstrong\u003e7\u003c/strong\u003e, 3698-3705 (2013).\u003c/li\u003e\n\u003cli\u003eSun, Q. M.\u003cem\u003e et al.\u003c/em\u003e Zeolite-encaged single-atom rhodium catalysts: Highly-efficient hydrogen generation and shape-selective tandem hydrogenation of nitroarenes. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e58\u003c/strong\u003e, 18570-18576 (2019).\u003c/li\u003e\n\u003cli\u003eDeng, X.\u003cem\u003e et al.\u003c/em\u003e Zeolite-encaged isolated platinum ions enable heterolytic dihydrogen activation and selective hydrogenations. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e143\u003c/strong\u003e, 20898-20906 (2021).\u003c/li\u003e\n\u003cli\u003eGoel, S., Zones, S. I. \u0026amp; Iglesia, E. Encapsulation of metal mlusters within MFI via interzeolite transformations and direct hydrothermal syntheses and catalytic consequences of their confinement. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e136\u003c/strong\u003e, 15280-15290 (2014).\u003c/li\u003e\n\u003cli\u003eWu, Z. J., Goel, S., Choi, M. \u0026amp; Iglesia, E. Hydrothermal synthesis of LTA-encapsulated metal clusters and consequences for catalyst stability, reactivity, and selectivity. \u003cem\u003eJ. Catal.\u003c/em\u003e \u003cstrong\u003e311\u003c/strong\u003e, 458-468 (2014).\u003c/li\u003e\n\u003cli\u003eGoel, S., Wu, Z., Zones, S. I. \u0026amp; Iglesia, E. Synthesis and catalytic properties of metal clusters encapsulated within small-pore (SOD, GIS, ANA) zeolites. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e134\u003c/strong\u003e, 17688-17695 (2012).\u003c/li\u003e\n\u003cli\u003eSung, J. K.\u003cem\u003e et al.\u003c/em\u003e General synthetic route toward highly dispersed metal clusters enabled by poly(ionic liquid)s. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e139\u003c/strong\u003e, 8971-8976 (2017).\u003c/li\u003e\n\u003cli\u003eWang, C. L.\u003cem\u003e et al.\u003c/em\u003e Hydrolysis of ammonia-borane over Ni/ZIF-8 nanocatalyst: High efficiency, mechanism, and controlled hydrogen release. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e139\u003c/strong\u003e, 11610-11615 (2017).\u003c/li\u003e\n\u003cli\u003eLiu, Y.\u003cem\u003e et al.\u003c/em\u003e Embedding high loading and uniform Ni nanoparticles into silicalite-1 zeolite for dry reforming of methane. \u003cem\u003eAppl. Catal.s B-Environ.\u003c/em\u003e \u003cstrong\u003e307\u003c/strong\u003e, 121202-121210 (2022).\u003c/li\u003e\n\u003cli\u003eIkuno, T.\u003cem\u003e et al.\u003c/em\u003e Methane Oxidation to methanol catalyzed by Cu-Oxo clusters stabilized in NU-1000 metal-organic framework. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e139\u003c/strong\u003e, 10294-10301 (2017).\u003c/li\u003e\n\u003cli\u003eLiu, W. G.\u003cem\u003e et al.\u003c/em\u003e A durable nickel single-atom catalyst for hydrogenation reactions and cellulose valorization under harsh conditions. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e57\u003c/strong\u003e, 7071-7075 (2018).\u003c/li\u003e\n\u003cli\u003eIZA-SC. International Zeolite Association. Database of Zeolite Structures; http://www.izastructure.org/databases.\u003c/li\u003e\n\u003cli\u003eSnyder, B. E. R.\u003cem\u003e et al.\u003c/em\u003e The active site of low-temperature methane hydroxylation in iron-containing zeolites. \u003cem\u003eNature\u003c/em\u003e \u003cstrong\u003e536\u003c/strong\u003e, 317-321 (2016).\u003c/li\u003e\n\u003cli\u003eLu, T. \u0026amp; Chen, F. Multiwfn: A multifunctional wavefunction analyzer. \u003cem\u003eJ. Comput. Chem.\u003c/em\u003e \u003cstrong\u003e33\u003c/strong\u003e, 580-592 (2011).\u003c/li\u003e\n\u003cli\u003eChai, Y. C.\u003cem\u003e et al.\u003c/em\u003e Acetylene-selective hydrogenation catalyzed by cationic confined in zeolite. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e141\u003c/strong\u003e, 9920-9927 (2019).\u003c/li\u003e\n\u003cli\u003eWang, J.\u003cem\u003e et al.\u003c/em\u003e Isolated palladium atoms dispersed on silicoaluminophosphate-31 (SAPO-31) for the semihydrogenation of alkynes. \u003cem\u003eACS Appl. Nano Mater.\u003c/em\u003e \u003cstrong\u003e4\u003c/strong\u003e, 861-868 (2020).\u003c/li\u003e\n\u003cli\u003eFan, Y.\u003cem\u003e et al.\u003c/em\u003e Efficient single-atom Ni for catalytic transfer hydrogenation of furfural to furfuryl alcohol. \u003cem\u003eJ. Mater. Chem. A\u003c/em\u003e \u003cstrong\u003e9\u003c/strong\u003e, 1110-1118 (2021).\u003c/li\u003e\n\u003cli\u003eSievers, C.\u003cem\u003e et al.\u003c/em\u003e Acid-catalyzed conversion of sugars and furfurals in an ionic-liquid phase. \u003cem\u003eChemSusChem\u003c/em\u003e \u003cstrong\u003e2\u003c/strong\u003e, 665-671 (2009).\u003c/li\u003e\n\u003cli\u003eMariscal, R., Maireles-Torres, P., Ojeda, M., S\u0026aacute;daba, I. \u0026amp; Granados, M. L. Furfural: a renewable and versatile platform molecule for the synthesis of chemicals and fuels. \u003cem\u003eEnerg Environ. Sci.\u003c/em\u003e \u003cstrong\u003e9\u003c/strong\u003e, 1144-1189 (2016).\u003c/li\u003e\n\u003cli\u003eBohre, A., Dutta, S., Saha, B. \u0026amp; Abu-Omar, M. M. Upgrading furfurals to drop-in biofuels: An overview. \u003cem\u003eACS Sustain. Chem. Eng.\u003c/em\u003e \u003cstrong\u003e3\u003c/strong\u003e, 1263-1277 (2015).\u003c/li\u003e\n\u003cli\u003eJoo, S. H.\u003cem\u003e et al.\u003c/em\u003e Ordered nanoporous arrays of carbon supporting high dispersions of platinum nanoparticles. \u003cem\u003eNature\u003c/em\u003e \u003cstrong\u003e412\u003c/strong\u003e, 169-172 (2001).\u003c/li\u003e\n\u003cli\u003eJia, P., Lan, X., Li, X. \u0026amp; Wang, T. Highly active and selective NiFe/SiO\u003csub\u003e2\u003c/sub\u003e bimetallic catalyst with optimized solvent effect for the liquid-phase hydrogenation of furfural to furfuryl alcohol. \u003cem\u003eACS Sustainable Chem. \u0026amp; Eng.\u003c/em\u003e \u003cstrong\u003e6\u003c/strong\u003e, 13287-13295 (2018).\u003c/li\u003e\n\u003cli\u003eChen, S., Wojcieszak, R., Dumeignil, F., Marceau, E. \u0026amp; Royer, S. How catalysts and experimental conditions determine the selective hydroconversion of furfural and 5-hydroxymethylfurfural. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e118\u003c/strong\u003e, 11023-11117 (2018).\u003c/li\u003e\n\u003cli\u003eKotbagi, T. V., Gurav, H. R., Nagpure, A. S., Chilukuri, S. V. \u0026amp; Bakker, M. G. Highly efficient nitrogen-doped hierarchically porous carbon supported Ni nanoparticles for the selective hydrogenation of furfural to furfuryl alcohol. \u003cem\u003eRSC Adv.\u003c/em\u003e \u003cstrong\u003e6\u003c/strong\u003e, 67662-67668 (2016).\u003c/li\u003e\n\u003cli\u003eLin, W.\u003cem\u003e et al.\u003c/em\u003e Surface Synergetic Effects of Ni-ReO for promoting the mild hydrogenation of furfural to tetrahydrofurfuryl alcohol. \u003cem\u003eACS Catal.\u003c/em\u003e \u003cstrong\u003e13\u003c/strong\u003e, 11256-11267 (2023).\u003c/li\u003e\n\u003cli\u003eLiu, L., Lou, H. \u0026amp; Chen, M. Selective hydrogenation of furfural to tetrahydrofurfuryl alcohol over Ni/CNTs and bimetallic Cu Ni/CNTs catalysts. \u003cem\u003eInt. J. Hydrogen Energy \u003c/em\u003e\u003cstrong\u003e41\u003c/strong\u003e, 14721-14731 (2016).\u003c/li\u003e\n\u003cli\u003eRodiansono, R., Hara, T., Ichikuni, N. \u0026amp; Shimazu, S. Development of nanoporous Ni-Sn alloy and application for chemoselective hydrogenation of furfural to furfuryl alcohol. \u003cem\u003eBull. Chem. React. Eng. Catal.\u003c/em\u003e \u003cstrong\u003e9\u003c/strong\u003e, 53-59 (2014).\u003c/li\u003e\n\u003cli\u003eZhang, J., Mao, D., Zhang, H. \u0026amp; Wu, D. Improving furfural hydrogenation selectivity by enhanced Ni-TiO\u003csub\u003e2\u003c/sub\u003e electronic interaction. \u003cem\u003eAppl. Catal. A: Gen.\u003c/em\u003e \u003cstrong\u003e660\u003c/strong\u003e, 119206-119217 (2023).\u003c/li\u003e\n\u003cli\u003eWu, J.\u003cem\u003e et al.\u003c/em\u003e Efficient and versatile CuNi alloy nanocatalysts for the highly selective hydrogenation of furfural. \u003cem\u003eAppl. Catal. B: Environ.\u003c/em\u003e \u003cstrong\u003e203\u003c/strong\u003e, 227-236 (2017).\u003c/li\u003e\n\u003cli\u003eYang, Y.\u003cem\u003e et al.\u003c/em\u003e Aqueous phase hydrogenation of furfural to tetrahydrofurfuryl alcohol on alkaline earth metal modified Ni/Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e. \u003cem\u003eRSC Adv.\u003c/em\u003e \u003cstrong\u003e6\u003c/strong\u003e, 51221-51228 (2016).\u003c/li\u003e\n\u003cli\u003eTian, Y. J.\u003cem\u003e et al.\u003c/em\u003e Template guiding for the encapsulation of uniformly subnanometric platinum clusters in Beta-zeolites enabling high catalytic activity and stability. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e60\u003c/strong\u003e, 21713-21717 (2021).\u003c/li\u003e\n\u003cli\u003eWang, L., Ma, Y., Li, H., Luo, W. \u0026amp; Liu, J. Screening support effect of Pt/MOx for selective hydrogenation of cinnamaldehyde. \u003cem\u003eJ. Catal.\u003c/em\u003e \u003cstrong\u003e431\u003c/strong\u003e, 115391-115398 (2024).\u003c/li\u003e\n\u003cli\u003eKostyniuk, A., Bajec, D. \u0026amp; Likozar, B. Catalytic hydrogenation, hydrocracking and isomerization reactions of biomass tar model compound mixture over Ni-modified zeolite catalysts in packed bed reactor. \u003cem\u003eRenew. Ener.g\u003c/em\u003e \u003cstrong\u003e167\u003c/strong\u003e, 409-424 (2021).\u003c/li\u003e\n\u003cli\u003eMoussa, S., Concepci\u0026oacute;n, P., Arribas, M. A. \u0026amp; Mart\u0026iacute;nez, A. The nature of active Ni sites and the role of Al species in the oligomerization of ethylene on mesoporous Ni-Al-MCM-41 catalysts. \u003cem\u003eAppl. Catal. A: Gen.\u003c/em\u003e \u003cstrong\u003e608\u003c/strong\u003e, 117831-117840 (2020).\u003c/li\u003e\n\u003cli\u003eYan, P.\u003cem\u003e et al.\u003c/em\u003e Facile and eco-friendly approach to produce confined metal cluster catalysts. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e145\u003c/strong\u003e, 9718-9728 (2023).\u003c/li\u003e\n\u003cli\u003eMaia, A. J., Louis, B., Lam, Y. L. \u0026amp; Pereira, M. M. Ni-ZSM-5 catalysts: Detailed characterization of metal sites for proper catalyst design. \u003cem\u003eJ. Catal.\u003c/em\u003e \u003cstrong\u003e269\u003c/strong\u003e, 103-109 (2010).\u003c/li\u003e\n\u003cli\u003eZhang, Q., Jiang, X., Su, Y., Zhao, Y. \u0026amp; Qiao, B. Catalytic propane dehydrogenation by anatase supported Ni single-atom catalysts. \u003cem\u003eChin. J. Catal.\u003c/em\u003e \u003cstrong\u003e57\u003c/strong\u003e, 105-113 (2024).\u003c/li\u003e\n\u003cli\u003eGuo, X. W. Hollow zeolite encapsulated Ni-Pt bimetals for sintering and coking resistant dry reforming of methane. \u003cem\u003eJ. Mater. Chem. A\u003c/em\u003e \u003cstrong\u003e3\u003c/strong\u003e, 16461-16468 (2015).\u003c/li\u003e\n\u003cli\u003eLiu, H.\u003cem\u003e et al.\u003c/em\u003e Encapsulation of Pd single-atom sites in zeolite for highly efficient semihydrogenation of alkynes. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e146\u003c/strong\u003e, 24033-24041 (2024).\u003c/li\u003e\n\u003cli\u003eAleksandrov, H. A.\u003cem\u003e et al.\u003c/em\u003e Precise identification of the infrared bands of the polycarbonyl complexes on Ni-MOR zeolite by\u003csup\u003e12\u003c/sup\u003eC\u003csup\u003e16\u003c/sup\u003eO-\u003csup\u003e13\u003c/sup\u003eC\u003csup\u003e18\u003c/sup\u003eO coadsorption and computational modeling. \u003cem\u003eThe J. Phys. Chem. C\u003c/em\u003e \u003cstrong\u003e116\u003c/strong\u003e, 22823-22831 (2012).\u003c/li\u003e\n\u003cli\u003eSalla, I., Montanari, T., Salagre, P., Cesteros, Y. \u0026amp; Busca, G. Fourier transform infrared spectroscopic study of the adsorption of CO and nitriles on Na-mordenite: Evidence of a new interaction. \u003cem\u003eJ. Phys. Chem. B\u003c/em\u003e \u003cstrong\u003e109\u003c/strong\u003e, 915-922 (2005).\u003c/li\u003e\n\u003cli\u003eCairon, O. \u0026amp; Bellat, J. P. Macroscopic and molecular insights from CO adsorption on NaY zeolite: A combined FTIR and manometric study. \u003cem\u003eJ. Phys. Chem. C\u003c/em\u003e \u003cstrong\u003e116\u003c/strong\u003e, 11195-11199 (2012).\u003c/li\u003e\n\u003cli\u003eMa, R.\u003cem\u003e et al.\u003c/em\u003e Insights into the nature of selective nickel sites on Ni/Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e catalysts for propane dehydrogenation. \u003cem\u003eACS. Catal.\u003c/em\u003e \u003cstrong\u003e12\u003c/strong\u003e, 12607-12616 (2022).\u003c/li\u003e\n\u003cli\u003eMart\u0026iacute;nez G\u0026oacute;mez-Aldarav\u0026iacute;, A., Paris, C., Moliner, M. \u0026amp; Mart\u0026iacute;nez, C. Design of bi-functional Ni-zeolites for ethylene oligomerization: Controlling Ni speciation and zeolite properties by one-pot and post-synthetic Ni incorporation. \u003cem\u003eJ. Catal.\u003c/em\u003e \u003cstrong\u003e426\u003c/strong\u003e, 140-152 (2023).\u003c/li\u003e\n\u003cli\u003eResini, C.\u003cem\u003e et al.\u003c/em\u003e An FFIR study of the dispersed Ni species on Ni-YSZ catalysts. \u003cem\u003eAppl. Catal. A-Gen.\u003c/em\u003e \u003cstrong\u003e353\u003c/strong\u003e, 137-143 (2009).\u003c/li\u003e\n\u003cli\u003eMoussa, S., Concepci\u0026oacute;n, P., Arribas, M. A. \u0026amp; Mart\u0026iacute;nez, A. Nature of active nickel sites and initiation mechanism for ethylene oligomerization on heterogeneous Ni-beta catalysts. \u003cem\u003eACS Catal.\u003c/em\u003e \u003cstrong\u003e8\u003c/strong\u003e, 3903-3912 (2018).\u003c/li\u003e\n\u003cli\u003eSu, H.\u003cem\u003e et al.\u003c/em\u003e Grouping effect of single nickel-N sites in nitrogen-doped carbon boosts hydrogen transfer coupling of alcohols and amines. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e57\u003c/strong\u003e, 15194-15198 (2018).\u003c/li\u003e\n\u003cli\u003eGu, J.\u003cem\u003e et al.\u003c/em\u003e Synergizing metal-support interactions and spatial confinement boosts dynamics of atomic nickel for hydrogenations. \u003cem\u003eNat. Nanotechnol.\u003c/em\u003e \u003cstrong\u003e16\u003c/strong\u003e, 1141-1149 (2021).\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Scheme","content":"\u003cp\u003eScheme 1 is available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-5796369/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5796369/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePrecisely tailoring metal single-atoms within zeolite scattfolds and understanding the origin of the unique behavior of such atomically dispersed catalysts are pivotal and challenge in chemistry and catalysis. Herein, we have successfully fabricated Ni single-atoms within BEA zeolite (Ni\u003csub\u003e1\u003c/sub\u003e@Beta) through a facile \u003cem\u003ein situ\u003c/em\u003e two-step hydrothermal strategy, notably without using any chelating agent for stabilizing Ni species. With the aid of advanced characterization techniques, such as aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM), X-ray absorption spectroscopy (XAS), etc, and combined with density functional theory (DFT) calculations, the nature and micro-environment of isolated Ni species, which are incorporated within 6-membered rings and stabilized by four skeletal oxygens of Beta zeolite, have been identified. The as-obtained Ni\u003csub\u003e1\u003c/sub\u003e@Beta exhibits a superior performance in terms of activity (with a turnover frequency (TOF) value up to 114.1 h\u003csup\u003e-1\u003c/sup\u003e) and stability (for 5 consecutive runs) in the selective hydrogenation of furfural, surpassing those of Ni nanoparticle analogues and previously reported Ni-based heterogeneous catalysts. This study provides an efficient strategy for the fabrication of non-noble metal single-atoms within zeolites, which could be of great help for the design of metal-zeolite combinations in the chemoselective reactions involved in biomass conversion and beyond.\u003c/p\u003e","manuscriptTitle":"Chelating-agent-free incorporation of isolated Ni single-atoms within BEA Zeolite for enhanced biomass hydrogenation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-15 06:09:33","doi":"10.21203/rs.3.rs-5796369/v1","editorialEvents":[{"type":"communityComments","content":1}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ca381a08-8bd3-4c1e-94a2-9f178876def6","owner":[],"postedDate":"January 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":42635314,"name":"Physical sciences/Chemistry/Catalysis/Catalyst synthesis"},{"id":42635315,"name":"Physical sciences/Chemistry/Catalysis/Heterogeneous catalysis"},{"id":42635316,"name":"Physical sciences/Chemistry/Green chemistry/Renewable energy"}],"tags":[],"updatedAt":"2025-01-15T09:36:33+00:00","versionOfRecord":[],"versionCreatedAt":"2025-01-15 06:09:33","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5796369","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5796369","identity":"rs-5796369","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}