Engineering Pt-O coordination microenvironment toward an active, durable, and antipoisoning catalyst in CO oxidation

Engineering Pt-O coordination microenvironment toward an active, durable, and antipoisoning catalyst in CO oxidation | 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 Engineering Pt-O coordination microenvironment toward an active, durable, and antipoisoning catalyst in CO oxidation Yong Luo, Bao-Ju Wang, Xin Zhang, Wenyao Chen, Hongzi Tan, Hai-Long Liao, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5859679/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 Platinum stands as a leading catalyst for oxidation reactions, with its catalytic performance intricately governed by the fine-tuning of its local coordination environment. In this study, we present an effective Na⁺-decoration strategy to reconstruct and stabilize the Pt-O coordination microenvironment, achieving remarkable enhancements in catalytic efficiency and durability. The Na⁺-stabilized Pt sites, characterized by a reduced Pt-O coordination number (CN), exhibit exceptional CO activation capabilities, delivering catalytic activity 20 times higher than Na + -free Pt atoms supported on ceria. Such decoration also promotes electron migration from Ce 3+ -oxygen vacancy (O V ) defects to PtO x clusters, preserving of a low Pt-O CN even under oxidative conditions, thereby significantly enhancing catalyst stability. Moreover, Na + -decorated Pt sites effectively suppress hydrocarbon adsorption, mitigating hydrocarbon poisoning during CO oxidation. By leveraging alkali cations to modulate Pt-O coordination, this strategy offers a versatile platform for addressing interface oxygen overstabilization of transition-metal atoms, heralding new opportunities in advancing heterogeneous catalysis for oxidation reactions. Physical sciences/Engineering/Chemical engineering Physical sciences/Chemistry/Catalysis/Heterogeneous catalysis Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction The catalytic performance of metals supported on oxide substrates is intricately governed by their ionic charge states and oxidation states, which is critical for driving a wide range of chemical transformations 1 , 2 . The electronic properties and surface reactivity of metal species are fundamentally dictated by their metal-oxygen (M-O) coordination microenvironment, establishing M-O interactions as a cornerstone in understanding catalytic behaviors 3 , 4 . Platinum-oxygen (Pt-O) interactions, in particular, have garnered significant attention due to their central role in numerous catalytic processes, including CO oxidation, hydrogenation, and environmental remediation 5 – 8 . Over the years, various strategies have been developed to finely tune the Pt-O coordination environment, such as alloying with other metals, doping with non-metals, engineering support interactions, and controlling particle size and morphology 9 – 13 . These approaches have deepened our understanding of the structure-activity relationships in Pt-based catalysts, providing key insights into their dynamic behavior under reaction conditions. Despite these advancements, achieving and maintaining a low Pt-O coordination number (CN) under oxidative conditions remains a formidable challenge. This is particularly critical for enhancing catalytic efficiency, selectivity, and durability, as low CN configurations are known to favor the activation of reactants like CO while suppressing undesired side reactions. The catalytic CO oxidation is widely recognized as a model reaction for probing the metal-oxygen structural dynamics due to the characteristic molecular rearrangements mediated by oxygen intermediates 14 . In the prototypical Pt/CeO₂ system, Ce⁴⁺ ions facilitate the transfer of d orbital electrons from Pt to their 4 f orbitals, resulting in positively charged Pt species with a high Pt-O CN 15 – 18 . Notably, Ke et al. identified that a Pt local structure with a relatively low Pt-O CN is optimally suited for CO oxidation, underscoring the significance of tailored Pt-O interactions for catalytic performance 19 . Traditional methods for reducing the Pt-O CN often rely on reduction pretreatment of the catalyst to destabilize excessive Pt-O coordination 20 , 21 . However, such reduced metallic Pt species are prone to reoxidation, reverting to high Pt-O CN configurations during prolonged oxidative reactions, thereby compromising catalytic activity and stability. This underscores the critical importance of developing strategies to construct and stabilize active Pt-O sites with intrinsically low Pt-O CN, ensuring consistent high performance in CO oxidation. Hence, advancing such methodologies is pivotal not only for CO oxidation but also for broader applications where precise control of metal-support interactions is essential. The catalytic oxidation of CO has also garnered significant attention due to its critical role in vehicle exhaust purification systems 22 – 25 . With the continuous advancements in internal combustion engine technologies, exhaust catalysts are increasingly required to exhibit high activity at low temperatures (< 150°C) to meet stringent fuel efficiency and emission standards 26 . In modern engines, the reduction in nitrogen oxides (NO x ) emissions has inadvertently resulted in higher concentrations of CO and hydrocarbons in exhaust gases 27 , 28 . The presence of hydrocarbons introduces a formidable challenge for Pt-based catalysts, as these species compete with CO for active Pt sites, significantly diminishing catalytic efficiency under low-temperature conditions 29 . This situation highlights the urgent need for exhaust catalysts that not only demonstrate exceptional low-temperature activity for CO oxidation but also possess robust resistance to hydrocarbon inhibition. Addressing this challenge is essential for the development of next-generation catalytic systems capable of meeting both environmental and operational demands in advanced automotive applications. In this study, we developed a Na⁺-decoration strategy to precisely regulate the Pt-O coordination microenvironment on ceria supports. Integrating catalytic performance evaluations, advanced characterizations, and density functional theory (DFT) calculations, we demonstrated the multifaceted roles of alkali cations (Na + ) in enhancing CO oxidation catalysis. The Na + -decorated Pt sites exhibited a significantly reduced Pt-O CN, accompanied by an increased CO coverage, which collectively enhanced CO activation. This decoration strategy also facilitated electron transfer from Ce 3+ -oxygen vacancy (O v ) defects to Pt, enabling the sustained low Pt-O CN even under severe oxidative conditions, thereby markedly improving the stability of the Pt/CeO 2 catalyst. Additionally, Na + -decoration substantially suppressed hydrocarbon adsorption on Pt active sites, effectively mitigating hydrocarbon poisoning and ensuring superior catalytic performance in CO oxidation. All these findings demonstrate Na + -decoration as a powerful approach for designing robust and efficient catalysts tailored for low-temperature oxidation applications. Results Highly active, durable, and antipoisoning performances in CO oxidation. The local coordination structure plays a pivotal role in determining catalytic activity. To precisely modulate the electronic state of Pt and tailor its Pt-O coordination structure, alkali cations (Na + ) were employed as electronic and structural modifiers 30 – 32 . Pt and Na were co-deposited on CeO 2 supports via an incipient wetness co-impregnation method, with the Na⁺-free Pt/CeO 2 catalyst serving as a benchmark for catalytic performance evaluation. A reduction pretreatment was applied to induce the restructuring of Pt sites prior to catalytic assessment. Notably, the reduced Pt(Na)/CeO 2 catalyst exhibited a significant enhancement in CO oxidation activity (Fig. 1 a). Intriguingly, the oxidized Pt sites stabilized by Na⁺ were not inherently active for CO oxidation. Despite the inferior overall performance of the Pt/CeO 2 catalyst (Fig. 1 b), its intrinsic activity, quantified as turnover frequencies (TOFs) per Pt site, was comparable to that of reported Pt cluster catalysts 14 , 33 – 35 . The Pt(Na)/CeO 2 catalyst demonstrated remarkable catalytic performance, achieving a T 90 (temperature for 90% CO conversion) of 92°C, significantly outperforming Pt/CeO 2 (T 90 = 245°C). At 100°C, the CO conversion rate on Pt(Na)/CeO 2 reached 1×10 − 5 mol CO ·g cat −1 ·s − 1 , corresponding to a TOF of 0.39 s − 1 . Impressively, the Na⁺-stabilized Pt atoms were 20 times more active than their Na + -free counterparts in catalyzing CO oxidation, highlighting the transformative effect of Na + -decoration on Pt site reactivity. The Pt(Na)/CeO 2 catalyst also demonstrated excellent stability during prolonged reaction tests (Fig. 1 c) and cycling evaluations (Supplementary Fig. 1), maintaining its high activity, whereas the catalytic performance of the Pt/CeO 2 catalyst progressively deteriorated. Automotive exhaust gases primarily consist of pollutants such as NO x , CO, and non-methane hydrocarbons 27 , 28 . The synthesized catalysts were also tested under simulated exhaust conditions to evaluate their performance. As shown in Fig. 1 b, the Pt(Na)/CeO 2 catalyst exhibited only a slight reduction in CO oxidation activity, whereas the catalytic performance of Pt/CeO 2 declined dramatically under the same conditions. At 120°C, the reaction rate on the Pt(Na)/CeO 2 catalyst was 1×10 − ⁵ mol CO ·g cat − ¹·s − ¹, corresponding to a turnover frequency (TOF) of 0.39 s − ¹. This performance was significantly superior to that of the Pt/CeO 2 catalyst, which achieved a reaction rate of 7×10 − 7 mol CO ·g cat −1 ·s − 1 and a TOF of 0.03 s − 1 , as well as other noble-metal-based catalysts reported in literatures (Supplementary Table 1) 23 , 36 . Both catalysts demonstrated comparable CO oxidation activity when NO gas was individually introduced into the reaction system (Supplementary Fig. 2). To investigate the inhibitory effects of hydrocarbons, propene (C 3 H 6 , 0.1%) was used as a model hydrocarbon and introduced into the reaction system. Remarkably, the CO oxidation activity of the Pt/CeO 2 catalyst plummeted by 76% in the presence of C 3 H 6 (Fig. 1 d), highlighting the susceptibility of Pt/CeO 2 to hydrocarbon-induced deactivation. In contrast, the Pt(Na)/CeO 2 catalyst exhibited significantly enhanced resistance to hydrocarbon poisoning, maintaining stable CO oxidation activity. Kinetic studies were conducted to unravel the intrinsic activity of the synthesized catalysts and to elucidate the promotional role of Na⁺. By applying the Weisz-Prater and Mears criteria (details provided in the Supplementary Material) 37 , 38 , it was verified that the reaction rates were unaffected by internal or external diffusion limitations. To ensure precise evaluation, CO conversions were maintained below 12% during the kinetic tests. The apparent activation energy ( E a ) of the Pt(Na)/CeO₂ catalyst (36.6 ± 1.7 kJ/mol) was significantly lower than that of the Pt/CeO₂ catalyst (81.5 ± 2.8 kJ/mol) (Fig. 1 e). This substantial reduction in E a underscores the Na⁺-induced modifications in the Pt local coordination structure, which enhanced the activation efficiency of reactants. The CO reaction orders for the Pt/CeO 2 and Pt(Na)/CeO 2 catalysts were determined to be 0.49 and approximately 0 (Fig. 1 f), respectively. This marked reduction in the reaction order of CO upon Na⁺-decoration indicates an enhanced CO coverage on Pt sites, thereby improving CO adsorption and activation on the Pt(Na)/CeO 2 catalyst. In contrast, the CO oxidation reaction catalyzed by Pt/C exhibited a negative reaction order with respect to CO (Supplementary Fig. 3a), indicating that an increase in CO concentration led to poisoning of the Pt active sites 39 , thereby diminishing the catalytic activity. The contrasting behavior in CO reaction orders between Pt/C and Pt/CeO 2 systems can be attributed to the role of the catalyst support. Ceria, a prototypical reducible oxide, provides reactive oxygen species (ROS) through lattice oxygen or oxygen adsorbed on vacancies, which participate in the CO oxidation reaction. Consequently, the reaction order of O 2 for the Pt/CeO 2 -catalyzed reaction was approximately zero (Supplementary Fig. 4), reflecting the abundant supply of ROS to facilitate the reaction with CO adsorbed on Pt sites. This dynamic prevented platinum poisoning, maintaining high catalytic activity. In contrast, the reaction order of O 2 for Pt/C catalysts ranged between 0 and 1 (Supplementary Fig. 3b) 39 , indicating a limited capacity of the Pt/C system to supply adequate ROS for CO oxidation. The deficiency of reactive oxygen in the Pt/C system allowed CO adsorption to poison Pt sites, thereby impairing its performance. As for the Pt/CeO 2 system, the strategic engineering of Pt local environment to modulate the CO activation is imperative for augmenting CO oxidation activity. Pt-O microenvironment characterization and electronic state analysis. Electron microscopy images of the Pt/CeO 2 and Pt(Na)/CeO 2 catalysts after air calcination are presented in Fig. 2 . Quantitative analysis of Pt species (Supplementary Fig. 5) revealed that the oxidized Na⁺-free Pt/CeO 2 catalyst exhibited a sub-cluster morphology of Pt, whereas oxidized single Pt atoms dominated on the Pt(Na)/CeO 2 catalyst. The Na⁺ decoration significantly enhanced the dispersion of oxidized Pt species on the ceria surface, attributed to the robust Pt-(O-Na) x interaction 9 , 40 . Following reduction treatment, the Pt species on the Pt/CeO 2 catalyst maintained their sub-cluster morphology (Supplementary Fig. 6), while the single-atom Pt on Pt(Na)/CeO 2 transformed into sub-cluster structures (Fig. 2 d). The mean particle sizes of Pt for the Pt/CeO₂ and Pt(Na)/CeO₂ catalysts were 0.68 ± 0.08 nm and 0.76 ± 0.09 nm, respectively (Supplementary Fig. 7). The negligible difference in particle size, both being below the 2 nm threshold, suggests that particle size effects on reactivity were not a primary factor 13 . Additionally, the specific surface area of the Pt(Na)/CeO 2 catalyst remained stable after reduction treatment (Supplementary Table 2), underscoring that the observed catalytic enhancements were driven by structural changes in Pt rather than surface area variations. Energy-dispersive spectroscopy (EDS) mapping (Fig. 2 e) revealed higher concentrations of Na dopants near Pt clusters, likely originating from strong interactions between Na⁺ and PtO x species. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) of CO adsorption was employed to examine the structural evolution of Pt. Before reduction treatment, CO adsorption bands centered at 2123 cm − 1 for Pt/CeO 2 and 2099 cm − 1 for Pt(Na)/CeO 2 corresponded to oxidized Pt clusters and oxidized single-atom Pt, respectively (Supplementary Fig. 8) 35 , 41 . The DRIFTS findings aligned with the microscopy results, confirming the Pt dispersion states. Reduction treatment under a flow of 1% CO and 5% H₂ in He induced a progressive redshift of the CO adsorption bands for Pt sites (Supplementary Figs. 9a-b). For Pt(Na)/CeO 2 , the CO adsorption band shifted dramatically (ranging from 1900 to 2000 cm − 1 ), indicating a significantly reduced Pt-O coordination number (CN). After switching to He flow to purge gaseous CO, the reduced Pt/CeO 2 exhibited classic metallic Pt 0 signatures (2066 ~ 2090 cm − 1 ) 42 . In contrast, the Pt(Na)/CeO 2 sample displayed a novel CO adsorption peak at 2037 cm − 1 (Supplementary Figs. 9c-d), indicative of extremely low Pt-O CN 41 – 43 . Post-CO oxidation, the Pt/CeO 2 catalyst reverted to oxidized Pt clusters (CO adsorption peak at 2122 cm − 1 ). Meanwhile, the low Pt-O CN on Pt(Na)/CeO 2 remained stable during the reaction (Fig. 2 f). These findings demonstrate that Na⁺ decoration reconstructed and stabilized the Pt coordination microenvironment, thereby significantly enhancing CO oxidation activity. To further probe the electronic structure, Pt L III -edge X-ray absorption near-edge structure (XANES) spectra were obtained for the reaction-spent catalysts. The white-line intensity (Fig. 2 g) confirmed the presence of oxidized Pt species on both catalysts and revealed electron transfer between Pt and the ceria support. Notably, Pt atoms on Pt(Na)/CeO 2 displayed a reduced cationic nature compared to Pt/CeO 2 , suggesting that Na + increased the electron density surrounding Pt. Fourier transform extended X-ray absorption fine structure (EXAFS) analysis confirmed the exclusive Pt-O coordination environment for both catalysts (Fig. 2 h). Unlike conventional three-dimensional platinum oxide clusters with Pt-Pt coordination, the Pt atoms on Pt/CeO 2 and Pt(Na)/CeO 2 were solely bridged by oxygen. The absence of long-range Pt-Pt or second-shell Pt-O features confirmed a monolayer Pt structure. The Pt-O CNs for Pt/CeO 2 and Pt(Na)/CeO 2 were 3.7 and 1.9, respectively, with an average Pt-O bond distance of 2.0 Å (Supplementary Table 3). This Na⁺-induced reduction in Pt-O CN created a local coordination environment optimized for CO activation. X-ray photoelectron spectroscopy (XPS) of Na 1 s further demonstrated shifts in the Pt(Na)/CeO 2 catalyst after reduction treatment (Supplementary Fig. 10), indicating interactions between Na + and the catalyst. This interaction likely occurred via oxygen within PtO x clusters or the ceria support, further contributing to the observed catalytic enhancements. Electronic migration/regulation mechanism. The Na + modification introduced profound changes in the electronic structure and surface chemistry of the Pt/CeO 2 catalyst, as elucidated by in situ DRIFTS and XAFS spectroscopy. These advanced characterizations revealed that Na + significantly mitigates the cationic nature of Pt and reduces the Pt-O CN, suggesting that Na + either inhibits electron transfer from Pt to the ceria support or promotes reverse electron flow from ceria to Pt. While the precise mechanism of this modulation remains to be fully elucidated, it presents a compelling avenue for future research. The defect characteristics and electronic states of the ceria support were investigated using XPS and electron paramagnetic resonance (EPR) spectroscopy. Formation of oxygen vacancies (V O ) on the CeO 2 surface led to the generation of Ce 3+ species as excess electrons localized on neighboring Ce 4+ cations. In the XPS Ce 3 d spectra (Fig. 3 a), among the ten deconvoluted peaks, the ν 0 (881 eV), ν′ (884.4 eV), µ 0 (898.5 eV), and µ′ (902.3 eV) peaks were indicative of Ce 3+ , while the remaining peaks corresponded to Ce 4+ species 44,45 . The Ce 3+ /(Ce 3+ +Ce 4+ ) ratio for the Na + -decorated Pt(Na)/CeO 2 catalyst was significantly lower (0.212) compared to the Pt/CeO 2 catalyst (0.276), implying reduced surface defect concentration. Similarly, in the XPS O 1 s spectra (Fig. 3 b), peaks at 529.3 eV, 531.7 eV, and 533.2 eV were assigned to lattice oxygen (O α ), adsorbed oxygen on surface oxygen vacancies (O β ), and adsorbed water (O γ ), respectively 46 , 47 . The O β /(O α +O β +O γ ) ratio for Pt(Na)/CeO 2 (0.242) was markedly lower than that for Pt/CeO 2 (0.338), confirming a significant reduction in oxygen vacancies. These results collectively indicate that Na + modification substantially diminishes the Ce 3+ -O V defect sites, thereby altering the electronic landscape of the catalyst. The EPR profile (Fig. 3 c) further supported this observation, displaying a characteristic signal at a g-value of 1.96, corresponding to defect-associated Ce 3+ -O V species 48 , 49 . The weaker resonance intensity observed for Pt(Na)/CeO 2 signifies a lower concentration of Ce 3+ -O V defects. The introduction of alkali cations facilitated enhanced electron transfer from oxygen defects, reducing the Ce 3+ -O V site density and promoting electron migration toward Pt. This phenomenon effectively lowered the Pt-O CN and stabilized the local Pt-O environment under oxidative conditions. The reducibility of surface oxygen species was examined using H 2 temperature-programmed reduction (TPR) profiles (Fig. 3 d). The reduction peaks observed within the temperature ranges of 50 ~ 200°C, 200 ~ 600°C, and 600 ~ 800°C corresponded to the reduction of oxygen species near Pt (Pt-O-Ce structure), surface Ce 4+ , and bulk CeO 2 , respectively 23 , 50 . For the Pt(Na)/CeO 2 catalyst, the reduction peak of the Pt-O-Ce structure shifted from 192°C to 153°C with decreased intensity, indicating a weakened Pt-O-Ce interaction and a reduced Pt-O CN. Concurrently, the reduction temperature of surface Ce 4+ was elevated, potentially due to accelerated electron transfer from ceria to Pt, which decreased the reducibility of Ce 4+ . In conventional Pt/CeO 2 systems, electron transfer from Pt to ceria promotes rapid lattice oxygen migration from ceria to oxidized Pt atoms 8 , 18 , resulting in a high Pt-O CN at Pt-O-Ce sites. This excessive oxygen stabilization hinders catalytic activity, particularly in CO oxidation. However, the presence of Na + reorients the electron transfer dynamics, redirecting electrons from Ce 3+ -O V defects to PtO x sites. This redistribution reduces the Pt oxidation state and Pt-O CN (Fig. 2 e), leading to enhanced CO oxidation performance. The observed decrease in Pt-O CN in the Na + modified subnanometric PtO x /CeO 2 catalyst underscores the critical role of alkali cation-induced electronic modulation in optimizing catalytic activity. Insight into the reason of improved durable and antipoisoning ability. During the catalytic stability test, the Pt(Na)/CeO 2 catalyst demonstrated remarkable stability, maintaining nearly constant activity, which attests to its robust structural integrity. In contrast, the Pt/CeO 2 catalyst exhibited a progressive decline in activity. To elucidate the nature and evolution of supported Pt species during CO oxidation, in situ DRIFTS (Diffuse Reflectance Infrared Fourier Transform Spectroscopy) was employed. The catalysts were pre-reduced under a mixed flow of CO and H 2 in He. Once CO saturation on the catalyst surface was achieved, the gas flow was switched to O 2 to assess the reactivity of the adsorbed CO intermediates. The results (Fig. 4 a) revealed that with increasing temperature, the metallic Pt 0 sites (2066 cm − 1 ) on the Pt/CeO 2 catalyst gradually shifted to higher wavenumbers (2117 cm − 1 ), indicative of the formation of more oxidized Pt species, characterized by a strong Pt-O-Ce bond. The absence of CO 2 formation underscored the inferior catalytic activity of the oxidized Pt species (Supplementary Fig. 11a). The transformation of the electronic and oxidation states of Pt within the local structure of the Pt/CeO 2 catalyst was responsible for the observed decrease in activity during the stability test. In the case of the Pt(Na)/CeO 2 catalyst, the CO adsorption peak at 2038 cm − 1 , attributed to Pt sites with low Pt-O coordination number (CN), disappeared at 50°C (Fig. 4 b), highlighting the superior low-temperature activity of the Na + -stabilized Pt local structure. Within this Pt coordination environment, an oxygen atom may bond with multiple Pt atoms, leading to the formation of Pt-O-Pt units, as evidenced by the CO adsorption peak (2081 cm − 1 ) 14 . These Pt-O-Pt sites exhibited exceptional performance in CO oxidation, with the CO adsorption peak vanishing at 80°C. The Pt sites on the Pt(Na)/CeO 2 catalyst remained unchanged throughout CO oxidation, emphasizing its remarkable stability. The Na + -decoration significantly enhanced the resistance of the Pt/CeO 2 catalyst to hydrocarbon poisoning during CO oxidation. To systematically assess the inhibitory impact of hydrocarbons on CO oxidation, C 3 H 6 was introduced into the reaction system during the in situ DRIFTS of CO oxidation. As shown in Figs. 4 c-d, the adsorption peaks in the range of 2800 ~ 3200 cm − 1 , corresponding to the C-H stretching bands of C 3 H 6 , were observed 51 . In the absence of C 3 H 6 , no such C-H stretching peaks were detected (Supplementary Fig. 11). Notably, the intensity of the C-H stretching bands was significantly diminished on the Pt(Na)/CeO 2 catalyst relative to the Pt/CeO 2 catalyst, indicating the latter's enhanced resistance to hydrocarbon poisoning. The weak C 3 H 6 adsorption on the Pt(Na)/CeO 2 catalyst aligns with its improved catalytic activity. Competitive adsorption between CO and C 3 H 6 on Pt sites is a well-established phenomenon 29 , 51 . With increasing reaction temperature, the low-coordinated Pt-O sites on the Pt/CeO 2 catalyst evolved into higher oxidation state Pt sites, which favored C 3 H 6 adsorption 29 . In contrast, the Na + -stabilized low-coordinated Pt-O sites on the Pt(Na)/CeO 2 catalyst remained stable, exhibiting only weak C 3 H 6 adsorption throughout the reaction. The transformation of the Pt-O local coordination environment on the Pt/CeO 2 catalyst facilitated enhanced C 3 H 6 adsorption, which contributed to the deactivation of the Pt/CeO 2 catalyst. Conversely, the minimal C 3 H 6 adsorption and limited interaction with active Pt sites on the Pt(Na)/CeO 2 catalyst likely accounted for its resistance to hydrocarbon inhibition. Identification of Na + -stabilized Pt local structure and its superior performance. To verify the alterations in the Pt-O coordination environment induced by Na + modification, DFT (Density Functional Theory) calculations were conducted. For the Pt/CeO 2 catalyst, a monolayer Pt 6 O 8 structure was modeled on the CeO 2 (111) surface (Fig. 5 a), constructed based on EXAFS data and the Pt particle size. In this configuration, Pt atoms were exclusively bridged by oxygen within their first coordination shell. Specifically, four Pt atoms were coordinated in a square-planar Pt-O 4 arrangement, while two Pt atoms exhibited a trigonal planar Pt-O 3 coordination geometry. For the Pt(Na)/CeO 2 catalyst, three Na atoms were incorporated into a triangular Pt 6 O 3 model on the CeO 2 (111) surface (Fig. 5 b), in line with the Pt to Na molar ratio of 2:1 (as confirmed by ICP-MS, Supplementary Table 3). In this structure, one Pt atom was coordinated in a Pt-O 3 configuration, while the remaining Pt atoms adopted a Pt-O 2 coordination geometry. Differential charge density analyses revealed notable differences in the electronic properties between the two catalysts. For the Pt/CeO 2 catalyst (Fig. 5 c and Supplementary Fig. 12a), Pt sites were inclined to lose electrons, resulting in increased electron density on the ceria surface oxygen atoms adjacent to the Pt atoms. In contrast, the Pt(Na)/CeO 2 catalyst displayed higher electron density around the Pt sites, with electron depletion observed on the ceria surface (Fig. 5 d and Supplementary Fig. 12b). The Na + modification effectively altered the electron transfer dynamics, thereby modifying the local microenvironment of the Pt-O coordination. The calculated CO adsorption wavenumbers for Pt-O 3 and Pt-O 4 sites on Pt/CeO 2 were in the range of 2120 ~ 2130 cm − 1 , closely matching the experimental values obtained from in situ DRIFTS of CO adsorption (Supplementary Fig. 13). The agreement between the calculated and experimental CO adsorption wavenumbers below 2040 cm − 1 (Supplementary Fig. 14) further confirmed the Na + -induced low Pt-O coordination structure. A comprehensive analysis incorporating HAADF-STEM, ICP-MS, XANES, EXAFS, XPS, and in situ DRIFTS of C-O vibrational frequencies supported the theoretical predictions of the Pt structure. These characterization techniques provided key insights into Pt size, chemical valence, and coordination environment, which established the baseline for further interpretation. To assess the influence of Na + modification on catalytic performance, the adsorption energies of CO molecules on Pt sites of both Pt/CeO 2 and Pt(Na)/CeO 2 catalysts were calculated. For the Pt/CeO 2 catalyst, the adsorption energies of CO on the Pt-O 4 and Pt-O 3 sites were determined to be -0.47 eV and − 1.2 eV, respectively. The predominance of the Pt-O 4 site in Pt/CeO 2 led to weaker CO adsorption, thereby diminishing the CO oxidation activity. In contrast, the Pt-O 3 and Pt-O 2 sites on the Pt(Na)/CeO 2 catalyst exhibited CO adsorption energies of -1.53 eV and − 1.86 eV, respectively. As shown in Supplementary Fig. 15, the reduction in Pt-O CN enhanced CO adsorption, leading to increased surface coverage of CO on Pt sites. This result was consistent with kinetic testing, which showed a decrease in the reaction order of CO with Na + modification. The absolute CO adsorption energy on Pt sites remained below − 2 eV, indicating that CO poisoning was not a significant factor. Furthermore, the alkali cation (Na + ) was found to mediate electron transfer from Ce 3+ -O V defects on the ceria support to Pt sites, thereby modulating the electronic state and the Pt-O coordination microenvironment. This interaction significantly enhanced the catalytic performance in CO oxidation. Discussion In this study, we present a highly effective Na + -decoration strategy to precisely modulate the Pt-O local coordination environment, resulting in significant improvements in catalytic activity, durability, and resistance to poisoning for CO oxidation. The incorporation of Na + alkali cations induces a structural transformation of Pt single atoms into more catalytically active Pt clusters, characterized by an ultra-low Pt-O CN, achieved through a reduction pretreatment. A comprehensive suite of characterizations, along with DFT calculations, demonstrated that Na + facilitates electronic transfer from Ce 3+ -O V defects to PtO x sites, thereby stabilizing the low CN Pt-O microenvironment under prolonged oxidative conditions. This innovative approach not only stabilizes Pt sites with low Pt-O coordination but also enhances CO adsorption, leading to improved CO oxidation performance. Additionally, it effectively mitigates hydrocarbon poisoning, addressing a key challenge in low-temperature (< 200°C) CO oxidation catalyzed by Pt-based systems. The significant electronic transfer effect induced by Na + underscores its broader applicability, providing a versatile strategy for engineering the metal-oxygen coordination environments of other transition metal systems supported on reducible oxides. These findings offer valuable insights for the rational design of catalysts with enhanced reactivity, stability, and resistance to poisoning, paving the way for advancements in heterogeneous catalysis. Methods Catalyst preparation. The nanostructured CeO 2 support was synthesized via a precipitation method. Specifically, a 40 mL NaOH solution (0.5313 mol/L) was slowly added dropwise to a 30 mL Ce(NO 3 ) 3 solution (0.1535 mol/L), followed by stirring for 1 hour. The resulting precipitate was thoroughly washed with deionized water three times. Subsequently, the solid was dried at 80°C for 12 hours and calcined at 500°C for 4 hours, with a heating rate of 5°C/min. Pt and Na were loaded onto the CeO 2 supports using an incipient wetness co-impregnation method, employing H 2 PtCl 6 and NaNO 3 solutions, respectively. The solid was then dried at 60°C for 5 hours and calcined at 300°C for 2 hours, with a heating rate of 2°C/min in static air. The surplus Na⁺ that did not contacting with the Pt/CeO 2 system was removed by washing with deionized water, after which the catalyst was dried. The Na⁺-containing Pt/CeO 2 catalyst was designated as Pt(Na)/CeO 2 , while the Na⁺-free Pt/CeO 2 served as a counterpart. Catalyst characterization. The concentrations of Pt and Na were quantified using PlasmaMS-300 inductively coupled plasma-mass spectrometry (ICP-MS). Nitrogen physisorption measurements were performed on a BETA201B analyzer at -196°C to determine the specific surface area and pore parameters of the catalysts. Aberration-corrected high angle annular dark field-scanning transmission electron microscopy (ac-HAADF-STEM) and energy-dispersive X-ray spectroscopy (EDS) mapping were conducted using a FEI OSIRIS microscope operated at 200 kV, providing detailed insights into the morphological and elemental distribution features of the catalysts. X-ray photoelectron spectroscopy (XPS) analyses were conducted utilizing a Thermo ESCA Lab-250Xi instrument, operated at a power of 252 W (15 kV and 15 mA). Electron paramagnetic resonance (EPR) measurements were carried out on a BRUKER EMX-8/2.7C X-band spectrometer, with a modulation frequency of 100 kHz. Hydrogen temperature-programmed reduction (H 2 -TPR) measurements were performed using an AutoChem II 2920 system, equipped with a thermal conductivity detector (TCD). For the TPR analysis, 0.1 g of catalyst was loaded into a fixed-bed reactor and pretreated with a helium flow (30 mL/min) at 200°C for 1 hour. After cooling to room temperature, the catalyst was exposed to a 5% H₂ in He mixture (30 mL/min) and heated to 800°C at a rate of 10°C/min. X-ray absorption fine structure (XAFS) spectra for the Pt L 3 -edge in fluorescence mode were obtained at the 1W1B beamline of the Beijing Synchrotron Radiation Facility. The Pt L 3 -edge spectra in the energy range of 11368–12463 eV were collected for the catalysts. Additionally, Pt foil and PtO 2 were tested as references for the Pt L₃-edge. The X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) data were analyzed using the Demeter software package. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements were performed using a Nicolet 6700 FTIR spectrometer equipped with a mercury cadmium telluride (MCT) detector. For the in situ DRIFTS analysis of CO chemisorption, the sample was exposed to a 1% CO in N 2 mixture at a flow rate of 30 mL/min for approximately 30 minutes. Prior to recording the DRIFTS spectrum, the system was purged with N 2 for 5 minutes to remove any residual gases. The DRIFTS spectrum was then recorded with 256 scans at a resolution of 4 cm − 1 . For the in situ DRIFTS investigation of CO oxidation, the sample was initially pretreated with a mixture of 1% CO and 5% H 2 in He at 200°C for 30 minutes. After cooling to room temperature, the sample was purged with the reaction gas to eliminate any extraneous components from the system. The system was subsequently heated to the desired temperature at a rate of 2°C/min. Before recording the DRIFTS spectrum, the sample was treated with the reaction gas for 5 minutes to ensure that the adsorption peaks in the IR spectra remained stable. Catalytic test and kinetics. The CO oxidation reaction was carried out in a fixed-bed reactor containing 50 mg of catalyst, under atmospheric pressure. Before conducting the catalytic evaluation, the synthesized catalysts were activated using a flow of 1% CO and 5% H₂ in He, and subsequently cooled to room temperature. The CO oxidation light-off performance was assessed at a heating rate of 2°C/min, with a weight hourly space velocity (WHSV) of 150,000 mL/(g·h). The reactive gas mixture comprised 0.4 vol.% CO, 10 vol.% O₂, and the balance was N₂. Additionally, 0.1 vol.% C₃H₆ was introduced to evaluate the catalysts' resistance to hydrocarbon poisoning. The gas composition of the product at the reactor outlet was analyzed using an online gas chromatography system (Agilent 7890B), equipped with a thermal conductivity detector. The turnover frequencies (TOFs) were determined by dividing the CO₂ generation rate by the number of active sites, as shown in Eq. 1. The quantity of active sites was calculated based on the total number of Pt atoms present on the ceria surface. To minimize the influence of heat and mass transfer effects, the kinetics experiments were conducted with CO conversions maintained below 12%. The weight hourly space velocity (WHSV) was set at 300,000 mL/(g·h) for Pt(Na)/CeO 2 and 150,000 mL/(g·h) for Pt/CeO 2 , respectively. During the evaluation of reaction orders with respect to CO and O 2 , kinetic tests were performed under gas flows containing 0.25 ~ 1.0% vol. CO and 2.5 ~ 10% vol. O 2 , with the balance being N 2 . These conditions allowed for a precise assessment of the reaction kinetics and the impact of varying CO and O 2 concentrations on the catalytic activity. Density functional theory (DFT) calculations. The spin-polarized electronic structures of all models were calculated using DFT with the projected augmented wave (PAW) method, as implemented in the Vienna Ab initio Simulation Package (VASP) code 14 , 52 . The generalized gradient approximation (GGA), parameterized by Perdew-Burke-Ernzerhof (PBE), was employed to describe the electronic interactions within our models. In the Brillouin zone, the k-point was set to the Gamma point, and Grimme's DFT-D3 model was utilized for van der Waals corrections. Geometric optimization was carried out with an energy cutoff of 450 eV. The optimization criteria were set such that the maximum force on each atom was less than 0.02 eV/Å, and the energy convergence standard was 10 − 5 eV. CeO 2 supercells (4 × 4 × 2) with exposed (111) surfaces were constructed, and a vacuum layer of 15 Å was added to minimize interactions between periodic images. The charge density difference was defined as Δ ρ = ρ AB - ρ A - ρ B , where ρ AB represents the electron density of the slab with adsorbed intermediates, ρ A is the electron density of the isolated slab, and ρ B is the electron density of the isolated intermediates. The adsorption energy ( E ad ) was calculated using the following equation: E ad = E sub+sur - ( E sub + E sur ) (2) Where, E sub+sur is the total energy of the surface adsorbed with the substrate, E sur is the energy of the surface without the substrate, and E sub is the energy of the substrate. References Lang R et al (2020) Single-atom catalysts based on the metal-oxide interaction. Chem Rev 120:11986–12043 Park JY et al (2015) Role of hot electrons and metal-oxide interfaces in surface chemistry and catalytic reactions. Chem Rev 115:2781–2817 Campbell CT (2012) Catalyst-support interactions: electronic perturbations. Nat Chem 4:597–598 Van Deelen TW et al (2019) Control of metal-support interactions in heterogeneous catalysts to enhance activity and selectivity. Nat Catal 2:955–970 Tan W et al (2022) Fine-tuned local coordination environment of Pt single atoms on ceria controls catalytic reactivity. 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Angew Chem Int Ed 54:13263–13267 Liang X et al (2022) Engineering the low-coordinated single cobalt atom to boost persulfate activation for enhanced organic pollutant oxidation. Appl Catal B 303:120877 Additional Declarations There is NO Competing Interest. Supplementary Files SupplementaryInformation.docx Supplementary Information 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-5859679","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":409051851,"identity":"452d0ad6-8bca-43e4-aba5-f806b6748c25","order_by":0,"name":"Yong Luo","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8klEQVRIiWNgGAWjYBACPigtx8DA2HiAsQHCk8CnhQ1KGwO1NIC18BCrJRFkPpFaJJKPSXzcUZu+tv0w0JYdh+XtGZgP3uZhsMvDrSUtTXLmmeO5284kArWcOWzYw8CWbM3DkFyMW0uOmTRv27HcbQdAWtoOJ/Aw8JhJ8zAcADsVn5Z0s/MPYVr4vxGjpSbB7AbCFjb8WnieJVvObDtguO0G0JbEM+mGPYfZjC3nGCTj1MLPnnzwxse2Onmz8+kPH3zcYS3P3t788MabCjucWoCABRgLhyHMBBDBDCIMcKsHKfnAwFCHV8UoGAWjYBSMcAAAtWhXDeVntdAAAAAASUVORK5CYII=","orcid":"","institution":"Beijing University of Chemical Technology","correspondingAuthor":true,"prefix":"","firstName":"Yong","middleName":"","lastName":"Luo","suffix":""},{"id":409051852,"identity":"c919e6da-58ec-433e-bf8d-99544dd68712","order_by":1,"name":"Bao-Ju Wang","email":"","orcid":"","institution":"Shandong University of Technology","correspondingAuthor":false,"prefix":"","firstName":"Bao-Ju","middleName":"","lastName":"Wang","suffix":""},{"id":409051853,"identity":"d2570be8-ad0a-4a92-9f45-d70ed87f9667","order_by":2,"name":"Xin Zhang","email":"","orcid":"","institution":"Beijing University of Chemical Technology","correspondingAuthor":false,"prefix":"","firstName":"Xin","middleName":"","lastName":"Zhang","suffix":""},{"id":409051854,"identity":"f057a957-0761-4d04-b3aa-cead245cc94e","order_by":3,"name":"Wenyao Chen","email":"","orcid":"https://orcid.org/0000-0001-8299-0607","institution":"East China University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Wenyao","middleName":"","lastName":"Chen","suffix":""},{"id":409051855,"identity":"1e8483c3-5f92-4178-bf08-152494154ef0","order_by":4,"name":"Hongzi Tan","email":"","orcid":"","institution":"Shandong University of Technology","correspondingAuthor":false,"prefix":"","firstName":"Hongzi","middleName":"","lastName":"Tan","suffix":""},{"id":409051856,"identity":"95127e51-c804-4dd6-95e0-a2f71a126c59","order_by":5,"name":"Hai-Long Liao","email":"","orcid":"","institution":"Beijing University of Chemical Technology","correspondingAuthor":false,"prefix":"","firstName":"Hai-Long","middleName":"","lastName":"Liao","suffix":""},{"id":409051857,"identity":"e9f498e8-533f-4d6d-81fc-616a1807f23b","order_by":6,"name":"Xiangxue Zhang","email":"","orcid":"","institution":"East China University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Xiangxue","middleName":"","lastName":"Zhang","suffix":""},{"id":409051858,"identity":"cdf72b6c-702e-4d44-9d1c-e141aac9f5be","order_by":7,"name":"Dingsheng Wang","email":"","orcid":"https://orcid.org/0000-0003-0074-7633","institution":"Tsinghua University","correspondingAuthor":false,"prefix":"","firstName":"Dingsheng","middleName":"","lastName":"Wang","suffix":""},{"id":409051859,"identity":"99998a60-103d-481e-a047-8b094f849970","order_by":8,"name":"Xuezhi Duan","email":"","orcid":"https://orcid.org/0000-0002-5843-5950","institution":"East China University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Xuezhi","middleName":"","lastName":"Duan","suffix":""},{"id":409051860,"identity":"2981a329-6b4e-4a49-ac43-d117c1df93be","order_by":9,"name":"Jian-Feng Chen","email":"","orcid":"https://orcid.org/0000-0003-1947-0603","institution":"Beijing University of Chemical Technology","correspondingAuthor":false,"prefix":"","firstName":"Jian-Feng","middleName":"","lastName":"Chen","suffix":""}],"badges":[],"createdAt":"2025-01-19 13:30:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5859679/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5859679/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":75145718,"identity":"63c2e889-ab3b-491b-b6f5-b5412ff46041","added_by":"auto","created_at":"2025-01-31 06:41:01","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":796309,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEnhancement of reaction performance and kinetics induced by Na\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e+\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e-modification. a\u003c/strong\u003e CO oxidation light-off curves of Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst before and after reduction treatment. Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e-O refers to the catalyst without reduction treatment. \u003cstrong\u003eb\u003c/strong\u003e CO oxidation light-off curves of Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalysts. Pt/CeO\u003csub\u003e2\u003c/sub\u003e-exhaust and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e-exhaust refer to that the catalysts were evaluated under simulated exhaust conditions ([CO] = 0.4%, [O\u003csub\u003e2\u003c/sub\u003e]=10%, [C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e] = 0.1%, [NO] = 0.05%, and [H\u003csub\u003e2\u003c/sub\u003eO] = 5% balanced with N\u003csub\u003e2\u003c/sub\u003e). \u003cstrong\u003ec\u003c/strong\u003e Stability test of Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalysts during CO oxidation. \u003cstrong\u003ed\u003c/strong\u003e Comparison of CO oxidation performance after introducing C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e flow. Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalysts were evaluated at 250 \u003csup\u003eo\u003c/sup\u003eC and 120 \u003csup\u003eo\u003c/sup\u003eC, respectively. \u003cstrong\u003ee\u003c/strong\u003e Arrhenius-type plot of CO oxidation rates at different temperatures with \u003cem\u003eE\u003c/em\u003e\u003csub\u003eapp\u003c/sub\u003e shown. \u003cstrong\u003ef\u003c/strong\u003e Reaction orders of CO over\u003cstrong\u003e \u003c/strong\u003ePt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalysts.\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-5859679/v1/58e32d616f0c01964f9584e0.png"},{"id":75145880,"identity":"d75f4bba-23a8-44eb-93da-5831c132c051","added_by":"auto","created_at":"2025-01-31 06:49:01","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1948756,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ePt structure evolution and structural characterization.\u003c/strong\u003e \u003cstrong\u003ea\u003c/strong\u003e Schematic diagram of Na\u003csup\u003e+\u003c/sup\u003e-induced evolution of Pt particle size. \u003cstrong\u003eb-d \u003c/strong\u003eAberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images of oxidized Pt/CeO\u003csub\u003e2\u003c/sub\u003e, oxidized Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e and reduced Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e, respectively. \u003cstrong\u003ee\u003c/strong\u003e STEM-EDS map of Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e. \u003cstrong\u003ef\u003c/strong\u003e \u003cem\u003eIn situ\u003c/em\u003e DRIFTS spectra of CO adsorption of Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e. \u003cstrong\u003eg-h\u003c/strong\u003e Normalized Pt L\u003csub\u003e3\u003c/sub\u003e-edge XANES and EXAFS spectra of Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e.\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-5859679/v1/35534ef3268af4e437017205.png"},{"id":75145882,"identity":"6c973a1f-7510-4c7f-b7c8-5fdcee83eecc","added_by":"auto","created_at":"2025-01-31 06:49:01","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1295925,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDefect properties characterization and diagram of electron transfer.\u003c/strong\u003e \u003cstrong\u003e(a)\u003c/strong\u003e Ce 3d and \u003cstrong\u003e(b)\u003c/strong\u003e O 1s XPS spectra of Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e. \u003cstrong\u003e(c)\u003c/strong\u003e EPR and \u003cstrong\u003e(d)\u003c/strong\u003e H\u003csub\u003e2\u003c/sub\u003e-TPR profiles of Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e. \u003cstrong\u003ee\u003c/strong\u003e Schematic diagram of electron transfer over Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e. Symbol of “□” represents oxygen vacancy. Color legend of atoms: Pt = brown, Ce = gray, Na = blue, O= pale green.\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-5859679/v1/561be0c8fc99eec6aaf9a8bc.png"},{"id":75145883,"identity":"7f6183a1-ce2a-46d5-89e6-de43a71b8ccc","added_by":"auto","created_at":"2025-01-31 06:49:01","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1136284,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eIn situ\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e DRIFTS characterization.\u003c/strong\u003e \u003cem\u003eIn situ\u003c/em\u003e DRIFTS of CO oxidation over \u003cstrong\u003e(a)\u003c/strong\u003e Pt/CeO\u003csub\u003e2\u003c/sub\u003e and \u003cstrong\u003e(b)\u003c/strong\u003e Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalysts. \u003cem\u003eIn situ\u003c/em\u003e DRIFTS of C-H stretching over \u003cstrong\u003e(c)\u003c/strong\u003e Pt/CeO\u003csub\u003e2\u003c/sub\u003e and \u003cstrong\u003e(d)\u003c/strong\u003e Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalysts. The test was conducted under reaction conditions.\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-5859679/v1/3b45fe8365f41ba00cf367b6.png"},{"id":75145725,"identity":"e0d7e096-635a-43fb-b610-d1e490b60891","added_by":"auto","created_at":"2025-01-31 06:41:01","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":2090993,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDFT calculations for stabilized Pt structure and charge density differences.\u003c/strong\u003e \u003cstrong\u003e(a)\u003c/strong\u003e Pt\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e8\u003c/sub\u003e/CeO\u003csub\u003e2\u003c/sub\u003e(111) model and \u003cstrong\u003e(b)\u003c/strong\u003e Na\u003csup\u003e+\u003c/sup\u003e-stabilized Pt\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e/CeO\u003csub\u003e2\u003c/sub\u003e(111) model. Color legend of atoms: Pt = blue, Ce = beige, Na = purple, O (in CeO\u003csub\u003e2\u003c/sub\u003e) = red, O (in Pt\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e8\u003c/sub\u003e, and Pt\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e) = gray. Charge density differences for \u003cstrong\u003e(c)\u003c/strong\u003e Pt/CeO\u003csub\u003e2\u003c/sub\u003e and \u003cstrong\u003e(d)\u003c/strong\u003e Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalysts.\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-5859679/v1/e62de7ccb1994df12236078b.png"},{"id":78275434,"identity":"5028eea1-c402-481e-8878-d3ecb434aa30","added_by":"auto","created_at":"2025-03-11 14:14:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":7996221,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5859679/v1/6d4865ec-9199-4607-9a69-42c00c235fe6.pdf"},{"id":75145720,"identity":"6b7efddc-960a-4a9b-b011-d30012ccc6a3","added_by":"auto","created_at":"2025-01-31 06:41:01","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":2132106,"visible":true,"origin":"","legend":"Supplementary Information","description":"","filename":"SupplementaryInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-5859679/v1/02cd6ae2bc458acc2899566e.docx"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Engineering Pt-O coordination microenvironment toward an active, durable, and antipoisoning catalyst in CO oxidation","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe catalytic performance of metals supported on oxide substrates is intricately governed by their ionic charge states and oxidation states, which is critical for driving a wide range of chemical transformations\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. The electronic properties and surface reactivity of metal species are fundamentally dictated by their metal-oxygen (M-O) coordination microenvironment, establishing M-O interactions as a cornerstone in understanding catalytic behaviors\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e,\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. Platinum-oxygen (Pt-O) interactions, in particular, have garnered significant attention due to their central role in numerous catalytic processes, including CO oxidation, hydrogenation, and environmental remediation\u003csup\u003e\u003cspan additionalcitationids=\"CR6 CR7\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. Over the years, various strategies have been developed to finely tune the Pt-O coordination environment, such as alloying with other metals, doping with non-metals, engineering support interactions, and controlling particle size and morphology\u003csup\u003e\u003cspan additionalcitationids=\"CR10 CR11 CR12\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. These approaches have deepened our understanding of the structure-activity relationships in Pt-based catalysts, providing key insights into their dynamic behavior under reaction conditions. Despite these advancements, achieving and maintaining a low Pt-O coordination number (CN) under oxidative conditions remains a formidable challenge. This is particularly critical for enhancing catalytic efficiency, selectivity, and durability, as low CN configurations are known to favor the activation of reactants like CO while suppressing undesired side reactions.\u003c/p\u003e \u003cp\u003eThe catalytic CO oxidation is widely recognized as a model reaction for probing the metal-oxygen structural dynamics due to the characteristic molecular rearrangements mediated by oxygen intermediates\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. In the prototypical Pt/CeO₂ system, Ce⁴⁺ ions facilitate the transfer of \u003cem\u003ed\u003c/em\u003e orbital electrons from Pt to their 4\u003cem\u003ef\u003c/em\u003e orbitals, resulting in positively charged Pt species with a high Pt-O CN\u003csup\u003e\u003cspan additionalcitationids=\"CR16 CR17\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. Notably, Ke et al. identified that a Pt local structure with a relatively low Pt-O CN is optimally suited for CO oxidation, underscoring the significance of tailored Pt-O interactions for catalytic performance\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. Traditional methods for reducing the Pt-O CN often rely on reduction pretreatment of the catalyst to destabilize excessive Pt-O coordination\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e,\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e. However, such reduced metallic Pt species are prone to reoxidation, reverting to high Pt-O CN configurations during prolonged oxidative reactions, thereby compromising catalytic activity and stability. This underscores the critical importance of developing strategies to construct and stabilize active Pt-O sites with intrinsically low Pt-O CN, ensuring consistent high performance in CO oxidation. Hence, advancing such methodologies is pivotal not only for CO oxidation but also for broader applications where precise control of metal-support interactions is essential.\u003c/p\u003e \u003cp\u003eThe catalytic oxidation of CO has also garnered significant attention due to its critical role in vehicle exhaust purification systems\u003csup\u003e\u003cspan additionalcitationids=\"CR23 CR24\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e. With the continuous advancements in internal combustion engine technologies, exhaust catalysts are increasingly required to exhibit high activity at low temperatures (\u0026lt;\u0026thinsp;150\u0026deg;C) to meet stringent fuel efficiency and emission standards\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e. In modern engines, the reduction in nitrogen oxides (NO\u003csub\u003ex\u003c/sub\u003e) emissions has inadvertently resulted in higher concentrations of CO and hydrocarbons in exhaust gases\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e,\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e. The presence of hydrocarbons introduces a formidable challenge for Pt-based catalysts, as these species compete with CO for active Pt sites, significantly diminishing catalytic efficiency under low-temperature conditions\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e. This situation highlights the urgent need for exhaust catalysts that not only demonstrate exceptional low-temperature activity for CO oxidation but also possess robust resistance to hydrocarbon inhibition. Addressing this challenge is essential for the development of next-generation catalytic systems capable of meeting both environmental and operational demands in advanced automotive applications.\u003c/p\u003e \u003cp\u003eIn this study, we developed a Na⁺-decoration strategy to precisely regulate the Pt-O coordination microenvironment on ceria supports. Integrating catalytic performance evaluations, advanced characterizations, and density functional theory (DFT) calculations, we demonstrated the multifaceted roles of alkali cations (Na\u003csup\u003e+\u003c/sup\u003e) in enhancing CO oxidation catalysis. The Na\u003csup\u003e+\u003c/sup\u003e-decorated Pt sites exhibited a significantly reduced Pt-O CN, accompanied by an increased CO coverage, which collectively enhanced CO activation. This decoration strategy also facilitated electron transfer from Ce\u003csup\u003e3+\u003c/sup\u003e-oxygen vacancy (O\u003csub\u003ev\u003c/sub\u003e) defects to Pt, enabling the sustained low Pt-O CN even under severe oxidative conditions, thereby markedly improving the stability of the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst. Additionally, Na\u003csup\u003e+\u003c/sup\u003e-decoration substantially suppressed hydrocarbon adsorption on Pt active sites, effectively mitigating hydrocarbon poisoning and ensuring superior catalytic performance in CO oxidation. All these findings demonstrate Na\u003csup\u003e+\u003c/sup\u003e-decoration as a powerful approach for designing robust and efficient catalysts tailored for low-temperature oxidation applications.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e \u003cb\u003eHighly active, durable, and antipoisoning performances in CO oxidation.\u003c/b\u003e The local coordination structure plays a pivotal role in determining catalytic activity. To precisely modulate the electronic state of Pt and tailor its Pt-O coordination structure, alkali cations (Na\u003csup\u003e+\u003c/sup\u003e) were employed as electronic and structural modifiers\u003csup\u003e\u003cspan additionalcitationids=\"CR31\" citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e. Pt and Na were co-deposited on CeO\u003csub\u003e2\u003c/sub\u003e supports via an incipient wetness co-impregnation method, with the Na⁺-free Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst serving as a benchmark for catalytic performance evaluation. A reduction pretreatment was applied to induce the restructuring of Pt sites prior to catalytic assessment. Notably, the reduced Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst exhibited a significant enhancement in CO oxidation activity (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). Intriguingly, the oxidized Pt sites stabilized by Na⁺ were not inherently active for CO oxidation. Despite the inferior overall performance of the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb), its intrinsic activity, quantified as turnover frequencies (TOFs) per Pt site, was comparable to that of reported Pt cluster catalysts\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e,\u003cspan additionalcitationids=\"CR34\" citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e. The Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst demonstrated remarkable catalytic performance, achieving a T\u003csub\u003e90\u003c/sub\u003e (temperature for 90% CO conversion) of 92\u0026deg;C, significantly outperforming Pt/CeO\u003csub\u003e2\u003c/sub\u003e (T\u003csub\u003e90\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;245\u0026deg;C). At 100\u0026deg;C, the CO conversion rate on Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e reached 1\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e mol\u003csub\u003eCO\u003c/sub\u003e\u0026middot;g\u003csub\u003ecat\u003c/sub\u003e\u003csup\u003e\u0026minus;1\u003c/sup\u003e\u0026middot;s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, corresponding to a TOF of 0.39 s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Impressively, the Na⁺-stabilized Pt atoms were 20 times more active than their Na\u003csup\u003e+\u003c/sup\u003e-free counterparts in catalyzing CO oxidation, highlighting the transformative effect of Na\u003csup\u003e+\u003c/sup\u003e-decoration on Pt site reactivity. The Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst also demonstrated excellent stability during prolonged reaction tests (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec) and cycling evaluations (Supplementary Fig.\u0026nbsp;1), maintaining its high activity, whereas the catalytic performance of the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst progressively deteriorated.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAutomotive exhaust gases primarily consist of pollutants such as NO\u003csub\u003ex\u003c/sub\u003e, CO, and non-methane hydrocarbons\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e,\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e. The synthesized catalysts were also tested under simulated exhaust conditions to evaluate their performance. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb, the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst exhibited only a slight reduction in CO oxidation activity, whereas the catalytic performance of Pt/CeO\u003csub\u003e2\u003c/sub\u003e declined dramatically under the same conditions. At 120\u0026deg;C, the reaction rate on the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst was 1\u0026times;10\u003csup\u003e\u0026minus;\u003c/sup\u003e⁵ mol\u003csub\u003eCO\u003c/sub\u003e\u0026middot;g\u003csub\u003ecat\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e\u0026sup1;\u0026middot;s\u003csup\u003e\u0026minus;\u003c/sup\u003e\u0026sup1;, corresponding to a turnover frequency (TOF) of 0.39 s\u003csup\u003e\u0026minus;\u003c/sup\u003e\u0026sup1;. This performance was significantly superior to that of the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst, which achieved a reaction rate of 7\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e mol\u003csub\u003eCO\u003c/sub\u003e\u0026middot;g\u003csub\u003ecat\u003c/sub\u003e\u003csup\u003e\u0026minus;1\u003c/sup\u003e\u0026middot;s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and a TOF of 0.03 s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, as well as other noble-metal-based catalysts reported in literatures (Supplementary Table\u0026nbsp;1) \u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e,\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u003c/sup\u003e. Both catalysts demonstrated comparable CO oxidation activity when NO gas was individually introduced into the reaction system (Supplementary Fig.\u0026nbsp;2). To investigate the inhibitory effects of hydrocarbons, propene (C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e, 0.1%) was used as a model hydrocarbon and introduced into the reaction system. Remarkably, the CO oxidation activity of the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst plummeted by 76% in the presence of C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed), highlighting the susceptibility of Pt/CeO\u003csub\u003e2\u003c/sub\u003e to hydrocarbon-induced deactivation. In contrast, the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst exhibited significantly enhanced resistance to hydrocarbon poisoning, maintaining stable CO oxidation activity.\u003c/p\u003e \u003cp\u003eKinetic studies were conducted to unravel the intrinsic activity of the synthesized catalysts and to elucidate the promotional role of Na⁺. By applying the Weisz-Prater and Mears criteria (details provided in the Supplementary Material) \u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e,\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e, it was verified that the reaction rates were unaffected by internal or external diffusion limitations. To ensure precise evaluation, CO conversions were maintained below 12% during the kinetic tests. The apparent activation energy (\u003cem\u003eE\u003c/em\u003e\u003csub\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sub\u003e) of the Pt(Na)/CeO₂ catalyst (36.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7 kJ/mol) was significantly lower than that of the Pt/CeO₂ catalyst (81.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8 kJ/mol) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ee). This substantial reduction in \u003cem\u003eE\u003c/em\u003e\u003csub\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sub\u003e underscores the Na⁺-induced modifications in the Pt local coordination structure, which enhanced the activation efficiency of reactants. The CO reaction orders for the Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalysts were determined to be 0.49 and approximately 0 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ef), respectively. This marked reduction in the reaction order of CO upon Na⁺-decoration indicates an enhanced CO coverage on Pt sites, thereby improving CO adsorption and activation on the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst. In contrast, the CO oxidation reaction catalyzed by Pt/C exhibited a negative reaction order with respect to CO (Supplementary Fig.\u0026nbsp;3a), indicating that an increase in CO concentration led to poisoning of the Pt active sites\u003csup\u003e\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u003c/sup\u003e, thereby diminishing the catalytic activity. The contrasting behavior in CO reaction orders between Pt/C and Pt/CeO\u003csub\u003e2\u003c/sub\u003e systems can be attributed to the role of the catalyst support. Ceria, a prototypical reducible oxide, provides reactive oxygen species (ROS) through lattice oxygen or oxygen adsorbed on vacancies, which participate in the CO oxidation reaction. Consequently, the reaction order of O\u003csub\u003e2\u003c/sub\u003e for the Pt/CeO\u003csub\u003e2\u003c/sub\u003e-catalyzed reaction was approximately zero (Supplementary Fig.\u0026nbsp;4), reflecting the abundant supply of ROS to facilitate the reaction with CO adsorbed on Pt sites. This dynamic prevented platinum poisoning, maintaining high catalytic activity. In contrast, the reaction order of O\u003csub\u003e2\u003c/sub\u003e for Pt/C catalysts ranged between 0 and 1 (Supplementary Fig.\u0026nbsp;3b) \u003csup\u003e\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u003c/sup\u003e, indicating a limited capacity of the Pt/C system to supply adequate ROS for CO oxidation. The deficiency of reactive oxygen in the Pt/C system allowed CO adsorption to poison Pt sites, thereby impairing its performance. As for the Pt/CeO\u003csub\u003e2\u003c/sub\u003e system, the strategic engineering of Pt local environment to modulate the CO activation is imperative for augmenting CO oxidation activity.\u003c/p\u003e \u003cp\u003e \u003cb\u003ePt-O microenvironment characterization and electronic state analysis.\u003c/b\u003e Electron microscopy images of the Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalysts after air calcination are presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Quantitative analysis of Pt species (Supplementary Fig.\u0026nbsp;5) revealed that the oxidized Na⁺-free Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst exhibited a sub-cluster morphology of Pt, whereas oxidized single Pt atoms dominated on the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst. The Na⁺ decoration significantly enhanced the dispersion of oxidized Pt species on the ceria surface, attributed to the robust Pt-(O-Na)\u003csub\u003ex\u003c/sub\u003e interaction\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u003c/sup\u003e. Following reduction treatment, the Pt species on the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst maintained their sub-cluster morphology (Supplementary Fig.\u0026nbsp;6), while the single-atom Pt on Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e transformed into sub-cluster structures (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ed). The mean particle sizes of Pt for the Pt/CeO₂ and Pt(Na)/CeO₂ catalysts were 0.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 nm and 0.76\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 nm, respectively (Supplementary Fig.\u0026nbsp;7). The negligible difference in particle size, both being below the 2 nm threshold, suggests that particle size effects on reactivity were not a primary factor\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. Additionally, the specific surface area of the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst remained stable after reduction treatment (Supplementary Table\u0026nbsp;2), underscoring that the observed catalytic enhancements were driven by structural changes in Pt rather than surface area variations. Energy-dispersive spectroscopy (EDS) mapping (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee) revealed higher concentrations of Na dopants near Pt clusters, likely originating from strong interactions between Na⁺ and PtO\u003csub\u003ex\u003c/sub\u003e species.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cem\u003eIn situ\u003c/em\u003e diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) of CO adsorption was employed to examine the structural evolution of Pt. Before reduction treatment, CO adsorption bands centered at 2123 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for Pt/CeO\u003csub\u003e2\u003c/sub\u003e and 2099 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e corresponded to oxidized Pt clusters and oxidized single-atom Pt, respectively (Supplementary Fig.\u0026nbsp;8)\u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e,\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e. The DRIFTS findings aligned with the microscopy results, confirming the Pt dispersion states. Reduction treatment under a flow of 1% CO and 5% H₂ in He induced a progressive redshift of the CO adsorption bands for Pt sites (Supplementary Figs.\u0026nbsp;9a-b). For Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e, the CO adsorption band shifted dramatically (ranging from 1900 to 2000 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), indicating a significantly reduced Pt-O coordination number (CN). After switching to He flow to purge gaseous CO, the reduced Pt/CeO\u003csub\u003e2\u003c/sub\u003e exhibited classic metallic Pt\u003csup\u003e0\u003c/sup\u003e signatures (2066\u0026thinsp;~\u0026thinsp;2090 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003csup\u003e42\u003c/sup\u003e. In contrast, the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e sample displayed a novel CO adsorption peak at 2037 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Supplementary Figs.\u0026nbsp;9c-d), indicative of extremely low Pt-O CN\u003csup\u003e\u003cspan additionalcitationids=\"CR42\" citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e. Post-CO oxidation, the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst reverted to oxidized Pt clusters (CO adsorption peak at 2122 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). Meanwhile, the low Pt-O CN on Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e remained stable during the reaction (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ef). These findings demonstrate that Na⁺ decoration reconstructed and stabilized the Pt coordination microenvironment, thereby significantly enhancing CO oxidation activity.\u003c/p\u003e \u003cp\u003eTo further probe the electronic structure, Pt \u003cem\u003eL\u003c/em\u003e\u003csub\u003eIII\u003c/sub\u003e-edge X-ray absorption near-edge structure (XANES) spectra were obtained for the reaction-spent catalysts. The white-line intensity (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eg) confirmed the presence of oxidized Pt species on both catalysts and revealed electron transfer between Pt and the ceria support. Notably, Pt atoms on Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e displayed a reduced cationic nature compared to Pt/CeO\u003csub\u003e2\u003c/sub\u003e, suggesting that Na\u003csup\u003e+\u003c/sup\u003e increased the electron density surrounding Pt. Fourier transform extended X-ray absorption fine structure (EXAFS) analysis confirmed the exclusive Pt-O coordination environment for both catalysts (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eh). Unlike conventional three-dimensional platinum oxide clusters with Pt-Pt coordination, the Pt atoms on Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e were solely bridged by oxygen. The absence of long-range Pt-Pt or second-shell Pt-O features confirmed a monolayer Pt structure. The Pt-O CNs for Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e were 3.7 and 1.9, respectively, with an average Pt-O bond distance of 2.0 \u0026Aring; (Supplementary Table\u0026nbsp;3). This Na⁺-induced reduction in Pt-O CN created a local coordination environment optimized for CO activation. X-ray photoelectron spectroscopy (XPS) of Na 1\u003cem\u003es\u003c/em\u003e further demonstrated shifts in the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst after reduction treatment (Supplementary Fig.\u0026nbsp;10), indicating interactions between Na\u003csup\u003e+\u003c/sup\u003e and the catalyst. This interaction likely occurred via oxygen within PtO\u003csub\u003ex\u003c/sub\u003e clusters or the ceria support, further contributing to the observed catalytic enhancements.\u003c/p\u003e \u003cp\u003e \u003cb\u003eElectronic migration/regulation mechanism.\u003c/b\u003e The Na\u003csup\u003e+\u003c/sup\u003e modification introduced profound changes in the electronic structure and surface chemistry of the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst, as elucidated by \u003cem\u003ein situ\u003c/em\u003e DRIFTS and XAFS spectroscopy. These advanced characterizations revealed that Na\u003csup\u003e+\u003c/sup\u003e significantly mitigates the cationic nature of Pt and reduces the Pt-O CN, suggesting that Na\u003csup\u003e+\u003c/sup\u003e either inhibits electron transfer from Pt to the ceria support or promotes reverse electron flow from ceria to Pt. While the precise mechanism of this modulation remains to be fully elucidated, it presents a compelling avenue for future research. The defect characteristics and electronic states of the ceria support were investigated using XPS and electron paramagnetic resonance (EPR) spectroscopy. Formation of oxygen vacancies (V\u003csub\u003eO\u003c/sub\u003e) on the CeO\u003csub\u003e2\u003c/sub\u003e surface led to the generation of Ce\u003csup\u003e3+\u003c/sup\u003e species as excess electrons localized on neighboring Ce\u003csup\u003e4+\u003c/sup\u003e cations. In the XPS Ce 3\u003cem\u003ed\u003c/em\u003e spectra (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea), among the ten deconvoluted peaks, the ν\u003csub\u003e0\u003c/sub\u003e (881 eV), ν\u0026prime; (884.4 eV), \u0026micro;\u003csub\u003e0\u003c/sub\u003e (898.5 eV), and \u0026micro;\u0026prime; (902.3 eV) peaks were indicative of Ce\u003csup\u003e3+\u003c/sup\u003e, while the remaining peaks corresponded to Ce\u003csup\u003e4+\u003c/sup\u003e species\u003csup\u003e44,45\u003c/sup\u003e. The Ce\u003csup\u003e3+\u003c/sup\u003e/(Ce\u003csup\u003e3+\u003c/sup\u003e+Ce\u003csup\u003e4+\u003c/sup\u003e) ratio for the Na\u003csup\u003e+\u003c/sup\u003e-decorated Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst was significantly lower (0.212) compared to the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst (0.276), implying reduced surface defect concentration. Similarly, in the XPS O 1\u003cem\u003es\u003c/em\u003e spectra (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb), peaks at 529.3 eV, 531.7 eV, and 533.2 eV were assigned to lattice oxygen (O\u003csub\u003eα\u003c/sub\u003e), adsorbed oxygen on surface oxygen vacancies (O\u003csub\u003eβ\u003c/sub\u003e), and adsorbed water (O\u003csub\u003eγ\u003c/sub\u003e), respectively\u003csup\u003e\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e,\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e\u003c/sup\u003e. The O\u003csub\u003eβ\u003c/sub\u003e/(O\u003csub\u003eα\u003c/sub\u003e+O\u003csub\u003eβ\u003c/sub\u003e+O\u003csub\u003eγ\u003c/sub\u003e) ratio for Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e (0.242) was markedly lower than that for Pt/CeO\u003csub\u003e2\u003c/sub\u003e (0.338), confirming a significant reduction in oxygen vacancies. These results collectively indicate that Na\u003csup\u003e+\u003c/sup\u003e modification substantially diminishes the Ce\u003csup\u003e3+\u003c/sup\u003e-O\u003csub\u003eV\u003c/sub\u003e defect sites, thereby altering the electronic landscape of the catalyst.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe EPR profile (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec) further supported this observation, displaying a characteristic signal at a g-value of 1.96, corresponding to defect-associated Ce\u003csup\u003e3+\u003c/sup\u003e-O\u003csub\u003eV\u003c/sub\u003e species\u003csup\u003e\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e,\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e\u003c/sup\u003e. The weaker resonance intensity observed for Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e signifies a lower concentration of Ce\u003csup\u003e3+\u003c/sup\u003e-O\u003csub\u003eV\u003c/sub\u003e defects. The introduction of alkali cations facilitated enhanced electron transfer from oxygen defects, reducing the Ce\u003csup\u003e3+\u003c/sup\u003e-O\u003csub\u003eV\u003c/sub\u003e site density and promoting electron migration toward Pt. This phenomenon effectively lowered the Pt-O CN and stabilized the local Pt-O environment under oxidative conditions. The reducibility of surface oxygen species was examined using H\u003csub\u003e2\u003c/sub\u003e temperature-programmed reduction (TPR) profiles (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed). The reduction peaks observed within the temperature ranges of 50\u0026thinsp;~\u0026thinsp;200\u0026deg;C, 200\u0026thinsp;~\u0026thinsp;600\u0026deg;C, and 600\u0026thinsp;~\u0026thinsp;800\u0026deg;C corresponded to the reduction of oxygen species near Pt (Pt-O-Ce structure), surface Ce\u003csup\u003e4+\u003c/sup\u003e, and bulk CeO\u003csub\u003e2\u003c/sub\u003e, respectively\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e,\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e\u003c/sup\u003e. For the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst, the reduction peak of the Pt-O-Ce structure shifted from 192\u0026deg;C to 153\u0026deg;C with decreased intensity, indicating a weakened Pt-O-Ce interaction and a reduced Pt-O CN. Concurrently, the reduction temperature of surface Ce\u003csup\u003e4+\u003c/sup\u003e was elevated, potentially due to accelerated electron transfer from ceria to Pt, which decreased the reducibility of Ce\u003csup\u003e4+\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn conventional Pt/CeO\u003csub\u003e2\u003c/sub\u003e systems, electron transfer from Pt to ceria promotes rapid lattice oxygen migration from ceria to oxidized Pt atoms\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e,\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e, resulting in a high Pt-O CN at Pt-O-Ce sites. This excessive oxygen stabilization hinders catalytic activity, particularly in CO oxidation. However, the presence of Na\u003csup\u003e+\u003c/sup\u003e reorients the electron transfer dynamics, redirecting electrons from Ce\u003csup\u003e3+\u003c/sup\u003e-O\u003csub\u003eV\u003c/sub\u003e defects to PtO\u003csub\u003ex\u003c/sub\u003e sites. This redistribution reduces the Pt oxidation state and Pt-O CN (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee), leading to enhanced CO oxidation performance. The observed decrease in Pt-O CN in the Na\u003csup\u003e+\u003c/sup\u003e modified subnanometric PtO\u003csub\u003ex\u003c/sub\u003e/CeO\u003csub\u003e2\u003c/sub\u003e catalyst underscores the critical role of alkali cation-induced electronic modulation in optimizing catalytic activity.\u003c/p\u003e \u003cp\u003e \u003cb\u003eInsight into the reason of improved durable and antipoisoning ability.\u003c/b\u003e During the catalytic stability test, the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst demonstrated remarkable stability, maintaining nearly constant activity, which attests to its robust structural integrity. In contrast, the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst exhibited a progressive decline in activity. To elucidate the nature and evolution of supported Pt species during CO oxidation, \u003cem\u003ein situ\u003c/em\u003e DRIFTS (Diffuse Reflectance Infrared Fourier Transform Spectroscopy) was employed. The catalysts were pre-reduced under a mixed flow of CO and H\u003csub\u003e2\u003c/sub\u003e in He. Once CO saturation on the catalyst surface was achieved, the gas flow was switched to O\u003csub\u003e2\u003c/sub\u003e to assess the reactivity of the adsorbed CO intermediates. The results (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea) revealed that with increasing temperature, the metallic Pt\u003csub\u003e0\u003c/sub\u003e sites (2066 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) on the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst gradually shifted to higher wavenumbers (2117 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), indicative of the formation of more oxidized Pt species, characterized by a strong Pt-O-Ce bond. The absence of CO\u003csub\u003e2\u003c/sub\u003e formation underscored the inferior catalytic activity of the oxidized Pt species (Supplementary Fig.\u0026nbsp;11a). The transformation of the electronic and oxidation states of Pt within the local structure of the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst was responsible for the observed decrease in activity during the stability test.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn the case of the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst, the CO adsorption peak at 2038 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, attributed to Pt sites with low Pt-O coordination number (CN), disappeared at 50\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb), highlighting the superior low-temperature activity of the Na\u003csup\u003e+\u003c/sup\u003e-stabilized Pt local structure. Within this Pt coordination environment, an oxygen atom may bond with multiple Pt atoms, leading to the formation of Pt-O-Pt units, as evidenced by the CO adsorption peak (2081 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003csup\u003e14\u003c/sup\u003e. These Pt-O-Pt sites exhibited exceptional performance in CO oxidation, with the CO adsorption peak vanishing at 80\u0026deg;C. The Pt sites on the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst remained unchanged throughout CO oxidation, emphasizing its remarkable stability.\u003c/p\u003e \u003cp\u003eThe Na\u003csup\u003e+\u003c/sup\u003e-decoration significantly enhanced the resistance of the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst to hydrocarbon poisoning during CO oxidation. To systematically assess the inhibitory impact of hydrocarbons on CO oxidation, C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e was introduced into the reaction system during the \u003cem\u003ein situ\u003c/em\u003e DRIFTS of CO oxidation. As shown in Figs.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec-d, the adsorption peaks in the range of 2800\u0026thinsp;~\u0026thinsp;3200 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, corresponding to the C-H stretching bands of C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e, were observed\u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e. In the absence of C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e, no such C-H stretching peaks were detected (Supplementary Fig.\u0026nbsp;11). Notably, the intensity of the C-H stretching bands was significantly diminished on the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst relative to the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst, indicating the latter's enhanced resistance to hydrocarbon poisoning. The weak C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e adsorption on the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst aligns with its improved catalytic activity.\u003c/p\u003e \u003cp\u003eCompetitive adsorption between CO and C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e on Pt sites is a well-established phenomenon\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e,\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e. With increasing reaction temperature, the low-coordinated Pt-O sites on the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst evolved into higher oxidation state Pt sites, which favored C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e adsorption\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e. In contrast, the Na\u003csup\u003e+\u003c/sup\u003e-stabilized low-coordinated Pt-O sites on the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst remained stable, exhibiting only weak C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e adsorption throughout the reaction. The transformation of the Pt-O local coordination environment on the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst facilitated enhanced C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e adsorption, which contributed to the deactivation of the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst. Conversely, the minimal C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e adsorption and limited interaction with active Pt sites on the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst likely accounted for its resistance to hydrocarbon inhibition.\u003c/p\u003e \u003cp\u003e \u003cb\u003eIdentification of Na\u003c/b\u003e \u003csup\u003e \u003cb\u003e+\u003c/b\u003e \u003c/sup\u003e \u003cb\u003e-stabilized Pt local structure and its superior performance.\u003c/b\u003e To verify the alterations in the Pt-O coordination environment induced by Na\u003csup\u003e+\u003c/sup\u003e modification, DFT (Density Functional Theory) calculations were conducted. For the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst, a monolayer Pt\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e8\u003c/sub\u003e structure was modeled on the CeO\u003csub\u003e2\u003c/sub\u003e(111) surface (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea), constructed based on EXAFS data and the Pt particle size. In this configuration, Pt atoms were exclusively bridged by oxygen within their first coordination shell. Specifically, four Pt atoms were coordinated in a square-planar Pt-O\u003csub\u003e4\u003c/sub\u003e arrangement, while two Pt atoms exhibited a trigonal planar Pt-O\u003csub\u003e3\u003c/sub\u003e coordination geometry. For the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst, three Na atoms were incorporated into a triangular Pt\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e model on the CeO\u003csub\u003e2\u003c/sub\u003e(111) surface (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eb), in line with the Pt to Na molar ratio of 2:1 (as confirmed by ICP-MS, Supplementary Table\u0026nbsp;3). In this structure, one Pt atom was coordinated in a Pt-O\u003csub\u003e3\u003c/sub\u003e configuration, while the remaining Pt atoms adopted a Pt-O\u003csub\u003e2\u003c/sub\u003e coordination geometry. Differential charge density analyses revealed notable differences in the electronic properties between the two catalysts. For the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ec and Supplementary Fig.\u0026nbsp;12a), Pt sites were inclined to lose electrons, resulting in increased electron density on the ceria surface oxygen atoms adjacent to the Pt atoms. In contrast, the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst displayed higher electron density around the Pt sites, with electron depletion observed on the ceria surface (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ed and Supplementary Fig.\u0026nbsp;12b). The Na\u003csup\u003e+\u003c/sup\u003e modification effectively altered the electron transfer dynamics, thereby modifying the local microenvironment of the Pt-O coordination.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe calculated CO adsorption wavenumbers for Pt-O\u003csub\u003e3\u003c/sub\u003e and Pt-O\u003csub\u003e4\u003c/sub\u003e sites on Pt/CeO\u003csub\u003e2\u003c/sub\u003e were in the range of 2120\u0026thinsp;~\u0026thinsp;2130 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, closely matching the experimental values obtained from \u003cem\u003ein situ\u003c/em\u003e DRIFTS of CO adsorption (Supplementary Fig.\u0026nbsp;13). The agreement between the calculated and experimental CO adsorption wavenumbers below 2040 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Supplementary Fig.\u0026nbsp;14) further confirmed the Na\u003csup\u003e+\u003c/sup\u003e-induced low Pt-O coordination structure. A comprehensive analysis incorporating HAADF-STEM, ICP-MS, XANES, EXAFS, XPS, and \u003cem\u003ein situ\u003c/em\u003e DRIFTS of C-O vibrational frequencies supported the theoretical predictions of the Pt structure. These characterization techniques provided key insights into Pt size, chemical valence, and coordination environment, which established the baseline for further interpretation. To assess the influence of Na\u003csup\u003e+\u003c/sup\u003e modification on catalytic performance, the adsorption energies of CO molecules on Pt sites of both Pt/CeO\u003csub\u003e2\u003c/sub\u003e and Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalysts were calculated. For the Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst, the adsorption energies of CO on the Pt-O\u003csub\u003e4\u003c/sub\u003e and Pt-O\u003csub\u003e3\u003c/sub\u003e sites were determined to be -0.47 eV and \u0026minus;\u0026thinsp;1.2 eV, respectively. The predominance of the Pt-O\u003csub\u003e4\u003c/sub\u003e site in Pt/CeO\u003csub\u003e2\u003c/sub\u003e led to weaker CO adsorption, thereby diminishing the CO oxidation activity. In contrast, the Pt-O\u003csub\u003e3\u003c/sub\u003e and Pt-O\u003csub\u003e2\u003c/sub\u003e sites on the Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e catalyst exhibited CO adsorption energies of -1.53 eV and \u0026minus;\u0026thinsp;1.86 eV, respectively. As shown in Supplementary Fig.\u0026nbsp;15, the reduction in Pt-O CN enhanced CO adsorption, leading to increased surface coverage of CO on Pt sites. This result was consistent with kinetic testing, which showed a decrease in the reaction order of CO with Na\u003csup\u003e+\u003c/sup\u003e modification. The absolute CO adsorption energy on Pt sites remained below \u0026minus;\u0026thinsp;2 eV, indicating that CO poisoning was not a significant factor. Furthermore, the alkali cation (Na\u003csup\u003e+\u003c/sup\u003e) was found to mediate electron transfer from Ce\u003csup\u003e3+\u003c/sup\u003e-O\u003csub\u003eV\u003c/sub\u003e defects on the ceria support to Pt sites, thereby modulating the electronic state and the Pt-O coordination microenvironment. This interaction significantly enhanced the catalytic performance in CO oxidation.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this study, we present a highly effective Na\u003csup\u003e+\u003c/sup\u003e-decoration strategy to precisely modulate the Pt-O local coordination environment, resulting in significant improvements in catalytic activity, durability, and resistance to poisoning for CO oxidation. The incorporation of Na\u003csup\u003e+\u003c/sup\u003e alkali cations induces a structural transformation of Pt single atoms into more catalytically active Pt clusters, characterized by an ultra-low Pt-O CN, achieved through a reduction pretreatment. A comprehensive suite of characterizations, along with DFT calculations, demonstrated that Na\u003csup\u003e+\u003c/sup\u003e facilitates electronic transfer from Ce\u003csup\u003e3+\u003c/sup\u003e-O\u003csub\u003eV\u003c/sub\u003e defects to PtO\u003csub\u003ex\u003c/sub\u003e sites, thereby stabilizing the low CN Pt-O microenvironment under prolonged oxidative conditions. This innovative approach not only stabilizes Pt sites with low Pt-O coordination but also enhances CO adsorption, leading to improved CO oxidation performance. Additionally, it effectively mitigates hydrocarbon poisoning, addressing a key challenge in low-temperature (\u0026lt;\u0026thinsp;200\u0026deg;C) CO oxidation catalyzed by Pt-based systems. The significant electronic transfer effect induced by Na\u003csup\u003e+\u003c/sup\u003e underscores its broader applicability, providing a versatile strategy for engineering the metal-oxygen coordination environments of other transition metal systems supported on reducible oxides. These findings offer valuable insights for the rational design of catalysts with enhanced reactivity, stability, and resistance to poisoning, paving the way for advancements in heterogeneous catalysis.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eCatalyst preparation.\u003c/strong\u003e The nanostructured CeO\u003csub\u003e2\u003c/sub\u003e support was synthesized via a precipitation method. Specifically, a 40 mL NaOH solution (0.5313 mol/L) was slowly added dropwise to a 30 mL Ce(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e3\u003c/sub\u003e solution (0.1535 mol/L), followed by stirring for 1 hour. The resulting precipitate was thoroughly washed with deionized water three times. Subsequently, the solid was dried at 80\u0026deg;C for 12 hours and calcined at 500\u0026deg;C for 4 hours, with a heating rate of 5\u0026deg;C/min.\u003c/p\u003e\n\u003cp\u003ePt and Na were loaded onto the CeO\u003csub\u003e2\u003c/sub\u003e supports using an incipient wetness co-impregnation method, employing H\u003csub\u003e2\u003c/sub\u003ePtCl\u003csub\u003e6\u003c/sub\u003e and NaNO\u003csub\u003e3\u003c/sub\u003e solutions, respectively. The solid was then dried at 60\u0026deg;C for 5 hours and calcined at 300\u0026deg;C for 2 hours, with a heating rate of 2\u0026deg;C/min in static air. The surplus Na⁺ that did not contacting with the Pt/CeO\u003csub\u003e2\u003c/sub\u003e system was removed by washing with deionized water, after which the catalyst was dried. The Na⁺-containing Pt/CeO\u003csub\u003e2\u003c/sub\u003e catalyst was designated as Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e, while the Na⁺-free Pt/CeO\u003csub\u003e2\u003c/sub\u003e served as a counterpart.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCatalyst characterization.\u003c/strong\u003e The concentrations of Pt and Na were quantified using PlasmaMS-300 inductively coupled plasma-mass spectrometry (ICP-MS). Nitrogen physisorption measurements were performed on a BETA201B analyzer at -196\u0026deg;C to determine the specific surface area and pore parameters of the catalysts. Aberration-corrected high angle annular dark field-scanning transmission electron microscopy (ac-HAADF-STEM) and energy-dispersive X-ray spectroscopy (EDS) mapping were conducted using a FEI OSIRIS microscope operated at 200 kV, providing detailed insights into the morphological and elemental distribution features of the catalysts.\u003c/p\u003e\n\u003cp\u003eX-ray photoelectron spectroscopy (XPS) analyses were conducted utilizing a Thermo ESCA Lab-250Xi instrument, operated at a power of 252 W (15 kV and 15 mA). Electron paramagnetic resonance (EPR) measurements were carried out on a BRUKER EMX-8/2.7C X-band spectrometer, with a modulation frequency of 100 kHz. Hydrogen temperature-programmed reduction (H\u003csub\u003e2\u003c/sub\u003e-TPR) measurements were performed using an AutoChem II 2920 system, equipped with a thermal conductivity detector (TCD). For the TPR analysis, 0.1 g of catalyst was loaded into a fixed-bed reactor and pretreated with a helium flow (30 mL/min) at 200\u0026deg;C for 1 hour. After cooling to room temperature, the catalyst was exposed to a 5% H₂ in He mixture (30 mL/min) and heated to 800\u0026deg;C at a rate of 10\u0026deg;C/min. X-ray absorption fine structure (XAFS) spectra for the Pt L\u003csub\u003e3\u003c/sub\u003e-edge in fluorescence mode were obtained at the 1W1B beamline of the Beijing Synchrotron Radiation Facility. The Pt L\u003csub\u003e3\u003c/sub\u003e-edge spectra in the energy range of 11368\u0026ndash;12463 eV were collected for the catalysts. Additionally, Pt foil and PtO\u003csub\u003e2\u003c/sub\u003e were tested as references for the Pt L₃-edge. The X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) data were analyzed using the Demeter software package.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eIn situ\u003c/em\u003e diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements were performed using a Nicolet 6700 FTIR spectrometer equipped with a mercury cadmium telluride (MCT) detector. For the \u003cem\u003ein situ\u003c/em\u003e DRIFTS analysis of CO chemisorption, the sample was exposed to a 1% CO in N\u003csub\u003e2\u003c/sub\u003e mixture at a flow rate of 30 mL/min for approximately 30 minutes. Prior to recording the DRIFTS spectrum, the system was purged with N\u003csub\u003e2\u003c/sub\u003e for 5 minutes to remove any residual gases. The DRIFTS spectrum was then recorded with 256 scans at a resolution of 4 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. For the \u003cem\u003ein situ\u003c/em\u003e DRIFTS investigation of CO oxidation, the sample was initially pretreated with a mixture of 1% CO and 5% H\u003csub\u003e2\u003c/sub\u003e in He at 200\u0026deg;C for 30 minutes. After cooling to room temperature, the sample was purged with the reaction gas to eliminate any extraneous components from the system. The system was subsequently heated to the desired temperature at a rate of 2\u0026deg;C/min. Before recording the DRIFTS spectrum, the sample was treated with the reaction gas for 5 minutes to ensure that the adsorption peaks in the IR spectra remained stable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCatalytic test and kinetics.\u003c/strong\u003e The CO oxidation reaction was carried out in a fixed-bed reactor containing 50 mg of catalyst, under atmospheric pressure. Before conducting the catalytic evaluation, the synthesized catalysts were activated using a flow of 1% CO and 5% H₂ in He, and subsequently cooled to room temperature. The CO oxidation light-off performance was assessed at a heating rate of 2\u0026deg;C/min, with a weight hourly space velocity (WHSV) of 150,000 mL/(g\u0026middot;h). The reactive gas mixture comprised 0.4 vol.% CO, 10 vol.% O₂, and the balance was N₂. Additionally, 0.1 vol.% C₃H₆ was introduced to evaluate the catalysts\u0026apos; resistance to hydrocarbon poisoning. The gas composition of the product at the reactor outlet was analyzed using an online gas chromatography system (Agilent 7890B), equipped with a thermal conductivity detector.\u003c/p\u003e\n\u003cp\u003eThe turnover frequencies (TOFs) were determined by dividing the CO₂ generation rate by the number of active sites, as shown in Eq. 1. The quantity of active sites was calculated based on the total number of Pt atoms present on the ceria surface.\u003c/p\u003e\n\u003cp\u003e\u003cimg 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\" style=\"width: 511px;\"\u003e\u003c/p\u003e\n\u003cp\u003eTo minimize the influence of heat and mass transfer effects, the kinetics experiments were conducted with CO conversions maintained below 12%. The weight hourly space velocity (WHSV) was set at 300,000 mL/(g\u0026middot;h) for Pt(Na)/CeO\u003csub\u003e2\u003c/sub\u003e and 150,000 mL/(g\u0026middot;h) for Pt/CeO\u003csub\u003e2\u003c/sub\u003e, respectively. During the evaluation of reaction orders with respect to CO and O\u003csub\u003e2\u003c/sub\u003e, kinetic tests were performed under gas flows containing 0.25\u0026thinsp;~\u0026thinsp;1.0% vol. CO and 2.5\u0026thinsp;~\u0026thinsp;10% vol. O\u003csub\u003e2\u003c/sub\u003e, with the balance being N\u003csub\u003e2\u003c/sub\u003e. These conditions allowed for a precise assessment of the reaction kinetics and the impact of varying CO and O\u003csub\u003e2\u003c/sub\u003e concentrations on the catalytic activity.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDensity functional theory (DFT) calculations.\u003c/strong\u003e The spin-polarized electronic structures of all models were calculated using DFT with the projected augmented wave (PAW) method, as implemented in the Vienna Ab initio Simulation Package (VASP) code\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e,\u003cspan class=\"CitationRef\"\u003e52\u003c/span\u003e\u003c/sup\u003e. The generalized gradient approximation (GGA), parameterized by Perdew-Burke-Ernzerhof (PBE), was employed to describe the electronic interactions within our models. In the Brillouin zone, the k-point was set to the Gamma point, and Grimme\u0026apos;s DFT-D3 model was utilized for van der Waals corrections. Geometric optimization was carried out with an energy cutoff of 450 eV. The optimization criteria were set such that the maximum force on each atom was less than 0.02 eV/\u0026Aring;, and the energy convergence standard was 10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e eV. CeO\u003csub\u003e2\u003c/sub\u003e supercells (4 \u0026times; 4 \u0026times; 2) with exposed (111) surfaces were constructed, and a vacuum layer of 15 \u0026Aring; was added to minimize interactions between periodic images. The charge density difference was defined as \u0026Delta;\u003cem\u003e\u0026rho;\u003c/em\u003e\u0026thinsp;=\u0026thinsp;\u003cem\u003e\u0026rho;\u003c/em\u003e\u003csub\u003eAB\u003c/sub\u003e - \u003cem\u003e\u0026rho;\u003c/em\u003e\u003csub\u003eA\u003c/sub\u003e - \u003cem\u003e\u0026rho;\u003c/em\u003e\u003csub\u003eB\u003c/sub\u003e, where \u0026rho;\u003csub\u003eAB\u003c/sub\u003e represents the electron density of the slab with adsorbed intermediates, \u003cem\u003e\u0026rho;\u003c/em\u003e\u003csub\u003eA\u003c/sub\u003e is the electron density of the isolated slab, and \u003cem\u003e\u0026rho;\u003c/em\u003e\u003csub\u003eB\u003c/sub\u003e is the electron density of the isolated intermediates. The adsorption energy (\u003cem\u003eE\u003c/em\u003e\u003csub\u003ead\u003c/sub\u003e) was calculated using the following equation:\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eE\u003c/em\u003e \u003csub\u003ead\u003c/sub\u003e =\u003cem\u003eE\u003c/em\u003e\u003csub\u003esub+sur\u003c/sub\u003e - (\u003cem\u003eE\u003c/em\u003e\u003csub\u003esub\u003c/sub\u003e + \u003cem\u003eE\u003c/em\u003e\u003csub\u003esur\u003c/sub\u003e) (2)\u003c/p\u003e\n\u003cp\u003eWhere, \u003cem\u003eE\u003c/em\u003e\u003csub\u003esub+sur\u003c/sub\u003e is the total energy of the surface adsorbed with the substrate, \u003cem\u003eE\u003c/em\u003e\u003csub\u003esur\u003c/sub\u003e is the energy of the surface without the substrate, and \u003cem\u003eE\u003c/em\u003e\u003csub\u003esub\u003c/sub\u003e is the energy of the substrate.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLang R et al (2020) Single-atom catalysts based on the metal-oxide interaction. 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Appl Catal B 303:120877\u003c/span\u003e\u003c/li\u003e\u003c/ol\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-5859679/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5859679/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePlatinum stands as a leading catalyst for oxidation reactions, with its catalytic performance intricately governed by the fine-tuning of its local coordination environment. In this study, we present an effective Na⁺-decoration strategy to reconstruct and stabilize the Pt-O coordination microenvironment, achieving remarkable enhancements in catalytic efficiency and durability. The Na⁺-stabilized Pt sites, characterized by a reduced Pt-O coordination number (CN), exhibit exceptional CO activation capabilities, delivering catalytic activity 20 times higher than Na\u003csup\u003e+\u003c/sup\u003e-free Pt atoms supported on ceria. Such decoration also promotes electron migration from Ce\u003csup\u003e3+\u003c/sup\u003e-oxygen vacancy (O\u003csub\u003eV\u003c/sub\u003e) defects to PtO\u003csub\u003ex\u003c/sub\u003e clusters, preserving of a low Pt-O CN even under oxidative conditions, thereby significantly enhancing catalyst stability. Moreover, Na\u003csup\u003e+\u003c/sup\u003e-decorated Pt sites effectively suppress hydrocarbon adsorption, mitigating hydrocarbon poisoning during CO oxidation. By leveraging alkali cations to modulate Pt-O coordination, this strategy offers a versatile platform for addressing interface oxygen overstabilization of transition-metal atoms, heralding new opportunities in advancing heterogeneous catalysis for oxidation reactions.\u003c/p\u003e","manuscriptTitle":"Engineering Pt-O coordination microenvironment toward an active, durable, and antipoisoning catalyst in CO oxidation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-31 06:40:56","doi":"10.21203/rs.3.rs-5859679/v1","editorialEvents":[{"type":"communityComments","content":0}],"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":"57a4a159-7704-477b-92f8-96f47e76d3c3","owner":[],"postedDate":"January 31st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":43617889,"name":"Physical sciences/Engineering/Chemical engineering"},{"id":43617890,"name":"Physical sciences/Chemistry/Catalysis/Heterogeneous catalysis"}],"tags":[],"updatedAt":"2025-03-11T14:06:06+00:00","versionOfRecord":[],"versionCreatedAt":"2025-01-31 06:40:56","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5859679","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5859679","identity":"rs-5859679","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}