Yolk-Shell Zeolite Nanoreactors Enable Multi‑Poison Resistance for NOx Reduction

Yolk-Shell Zeolite Nanoreactors Enable Multi‑Poison Resistance for NOx Reduction | 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 Yolk-Shell Zeolite Nanoreactors Enable Multi‑Poison Resistance for NO x Reduction Honggen Peng, Yonglong Li, Guobo Li, Rongxing Li, Jian Ji, Xiaonan Hu, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9293985/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract The practical application of ammonia selective catalytic reduction (NH 3 -SCR) for stationary NO x abatement is severely restricted by rapid catalyst deactivation in flue gases containing SO 2 and alkali metal. Although coupling zeolites with transition-metal oxides improves poisoning tolerance, most adopted loading or confining strategies cannot simultaneously ensure high redox-site content and effective protection. Herein, we realize a zeolite-confined nanoreactor concept by constructing a yolk-shell catalyst, in which high-content (>10 wt.%) MnFeO x nanoparticles are confined within a hollow ZSM-5 single-crystal shell, with the zeolite framework fully preserved. In situ X-ray absorption fine structure (XAFS) and diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS), together with density functional theory (DFT) calculations, reveal a synergistic dual-shielding mechanism: the ZSM-5 shell physically hinders SO 2 from attacking the active oxide core, while external Brønsted acid sites chemically suppress SO 2 adsorption and intercept alkali metal. Consequently, the catalyst maintains >90% NO x conversion with high N 2 selectivity under co-poisoning by SO 2 and K. This work establishes hollow zeolite-confined nanoreactors as a versatile platform for designing durable emission-control catalysts, enabling stable long-term operation under industrially relevant multi-poisoning conditions. Earth and environmental sciences/Environmental sciences/Environmental chemistry/Pollution remediation Physical sciences/Chemistry/Catalysis/Heterogeneous catalysis NH3-SCR NOx abatement Multiple poisons Yolk-shell Zeolite Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction The abatement of nitrogen oxides (NO x ) from industrial stationary sources (coal-fired power plants and waste incinerators, etc.) remains a critical environmental challenge due to their severe impact on air quality and human health 1-4 . Ammonia selective catalytic reduction (NH 3 -SCR) is currently one of the most efficient industrial technologies for NO x removal 5-7 . However, the practical longevity of SCR catalysts is severely compromised in real-world flue gas environments, where NO x coexists with potent poisons such as sulfur dioxide (SO 2 ) and alkali metal (e.g., K 2 O) 8,9 . These poisons cause rapid and serious deactivation, making the development of catalysts with simultaneous resistance to SO 2 and alkali poisoning a paramount challenge for sustainable industrial operation 10-13 . Coupling zeolites with transition-metal oxides has emerged as a promising approach because these components offer complementary functionalities 14-17 . Zeolites, such as ZSM-5, provide high surface area and Brønsted acidity capable of neutralizing alkali metal, whereas metal oxides (e.g., MnO x , FeO x , CeO x ) supply the redox activity required for SCR 18-20 . Yet conventional integration strategies (e.g., simple mixing, deposition, or impregnation) 16,17,21,22 leave oxide nanoparticles exposed on the external surface of the zeolite, making them vulnerable to sulfation and alkali poisoning, even when the oxide loading is increased 23,24 . To overcome this limitation, we envisioned a different architectural strategy: constructing a zeolite nanoreactor in which a high-content redox-active oxide core is encapsulated inside a porous acidic shell. In such a configuration, the zeolite shell would not merely confine the catalyst but actively regulate its interaction with the environment, allowing reactants to diffuse inward while intercepting poisons before they reach the active phase. This confined architecture could enable simultaneous preservation of high redox-site content and strong resistance to multi-component poisoning. We realize this concept by synthesizing a yolk-shell MnFeO x @YS-ZSM-5 catalyst through an impregnation-dissolution-recrystallization (IDR) strategy. The resulting nanoreactor consists of MnFeO x nanoparticles confined within a hollow single-crystalline ZSM-5 shell. Structural characterization, operando spectroscopy, and theory collectively reveal a dual-shielding mechanism combining physical isolation and chemical adsorption control. This architecture delivers outstanding SCR activity and stability under simultaneous SO 2 and alkali exposure and can be generalized to other mixed-metal oxides, establishing hollow zeolite nanoreactors as a new platform for durable NO x emission-control catalysis. Results Formation of the yolk - shell nanoreactor. The yolk-shell MnFeO x @YS-ZSM-5 nanoreactor was synthesized via an IDR strategy ( Fig . 1A ). In this architecture, crystalline ZSM-5 forms a hollow shell, while MnFeO x nanoparticles are confined as an internal yolk. Bulk ZSM-5 is first impregnated with Mn and Fe precursors and calcined to generate MnFeO x /ZSM-5, in which metal oxide are dispersed on the zeolite external surface. Subsequent hydrothermal treatment in tetrapropylammonium hydroxide (TPAOH) induces selective internal dissolution of the zeolite and simultaneous recrystallization at the exterior, ultimately yielding a hollow ZSM-5 shell that fully encapsulates the MnFeO x nanoparticles. Electron microscopy reveals a clear structural evolution during this process. Pristine ZSM-5 consists of well-defined blocky crystals with sharp edges and an average particle size of ~145 nm ( Fig s. S1 and S2 ). After impregnation, MnFeO x /ZSM-5 retains the original morphology ( Fig . S3 ), but transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS; Fig . S4 ) mapping confirm that Mn and Fe species are distributed on the external surface. In contrast, the final MnFeO x @YS-ZSM-5 nanoreactor exhibits a distinct yolk-shell architecture. Scanning electron microscopy (SEM) shows hollow cubic particles ( Fig . S5 ), while TEM ( Fig s. 1B , 1C , and S6 ) and high-angle annular dark-field scanning TEM (HAADF-STEM) image ( Fig . 1D ) unambiguously demonstrate that MnFeO x nanoparticles are confined within the internal cavity of hollow ZSM-5, with no detectable species on the outer surface. The nanoreactors maintain an average size of ~145 nm, with shell thicknesses ranging from ~10 to ~30 nm. Notably, the MnFeO x nanoparticles are preferentially located near the inner shell surface rather than at the geometric center. EDS elemental mappings ( Fig s. 1E and 1F ) and line-scan profiles ( Fig . S7 ) confirm that Mn and Fe are spatially confined inside the zeolite shell rather than on the external surface. Integrated differential phase-contrast STEM (iDPC-STEM) ( Fig s. 1G and S8 ) directly resolves the atomic-scale MFI framework of the ZSM-5 shell while simultaneously visualizing the encapsulated MnFeO x yolk. The corresponding Fourier transform pattern ( Fig . S8F ) reveals a well-ordered diffraction spot array, confirming the single-crystalline nature of the zeolite shell. Given that the zeolite micropores (~0.54 nm , Fig . 1H ) are much smaller than the MnFeO x nanoparticles (~8.73 nm), migration of the active phase into the zeolite channels is effectively prohibited. Nitrogen adsorption-desorption results ( Fig s. 1I and Fig . S9 ) confirm the hollow structure of MnFeO x @YS-ZSM-5, as evidenced by its distinctive H2-type hysteresis loop and increased total pore volume ( Table S1 ) 25 . XRD analysis ( Fig . S10 ) verifies that the ZSM-5 zeolite retains its MFI crystal structure without loss of crystallinity after the encapsulation process. Meanwhile, the strong attenuation of Fe 2p and Mn 2p signals in the X-ray photoelectron spectroscopy (XPS) spectra ( Fig . 1J ) of MnFeO x @YS-ZSM-5 provides further evidence consistent with the successful confinement of the MnFeO x metal oxide core within the zeolite shell. Time-dependent hydrothermal treatments reveal the mechanism underlying yolk-shell formation. Progressive development of internal voids is observed with increasing treatment duration, as evidenced by microscopy ( Fig s. S11 - S1 7 ) and N 2 adsorption-desorption results ( Fig . S1 8) , while XRD patterns ( Fig . S19 ) confirm that the MFI framework is preserved throughout the process. XPS results ( Fig . S 20 ) show pronounced Si enrichment and Al depletion on the external surface after TPAOH hydrothermal treatment, indicative of preferential internal Si dissolution and outward recrystallization of silicate species ( Fig . S21 ) 25 . The universality of the IDR strategy is further demonstrated through the successful synthesis of hollow ZSM-5 zeolite encapsulating MnCoO x or MnCeO x ( Fig s. S22 and S23 ). Both systems display well-defined yolk-shell architectures, as evidenced by adsorption-desorption profiles ( Fig s. S24 and S25 ) and XRD patterns ( Fig . S26 ), confirming that the zeolite crystallinity remains intact regardless of the metal oxide precursor. NH 3 -SCR performance and multi-poison resistance . To clarify the catalytic advantages of the yolk-shell MnFeO x @YS-ZSM-5 nanoreactor in NH 3 -SCR ( Fig . 2 A ), comparative catalysts (MnFeO x , MnFeO x /ZSM-5, and MnFeO x /S-1; the S-1 support is an aluminum-free zeolite with much weaker acidity than ZSM-5) were prepared ( Figs. S27 - S32 ; Table S1 ) and then evaluated. Pure MnFeO x shows high activity only below 200 °C, followed by rapid deactivation due to excessive NH 3 oxidation ( Fig. S33 ) and poor N 2 selectivity ( Fig. S34 ). Coupling MnFeO x with a zeolite broadens the operational window. Notably, MnFeO x @YS-ZSM-5 delivers the most robust performance, maintaining >80% NOₓ conversion across a wide temperature range of 220-500 °C, while MnFeO x /S-1 and MnFeO x /ZSM-5 display significantly compromised medium-high-temperature performance. Samples treated hydrothermally in TPAOH for different durations ( Fig . S35 ) all retain similarly wide temperature windows. Compared with reported MnFeO x -based catalysts ( Fig . S36 and Table S2 ), MnFeO x @YS-ZSM-5 exhibits a remarkably broader operational range. Kinetic analysis ( Fig . S37 and Tables S3 - S5 ) shows that all oxide-zeolite composites possess substantially lower apparent activation energies than pure MnFeO x . The SO 2 tolerance was evaluated at 246 °C with 50 ppm SO 2 ( Fig . 2B ). MnFeO x /ZSM-5 undergoes rapid deactivation, with NOₓ conversion dropping from 98% to 33% within 0.5 h and stabilizing below 39% after SO 2 was cut off. Pure MnFeO x shows only transient resistance before severe deterioration. In striking contrast, MnFeO x @YS-ZSM-5 stabilizes at ~83% conversion and rapidly recovers to ~90% once SO 2 is removed, demonstrating largely reversible deactivation. Pre-sulfidation experiments ( Fig . S38 ) further confirm the better SO 2 resistance of the yolk-shell nanoreactor. To decouple the effects of hollow morphology from encapsulation, a control catalyst consisting of MnFeO x supported on hollow ZSM-5 (MnFeO x /Hollow-ZSM-5) was synthesized ( Figs . S39 - S40 ). Although this catalyst exhibits comparable SCR activity ( Fig . S41 ), its SO 2 tolerance is markedly inferior ( Fig . S42 ), establishing that the superior durability of MnFeO x @YS-ZSM-5 arises from the dual-shielding effect of the intact zeolite shell (physical protection of MnFeO x from SO 2 and chemical regulation of surface adsorption) rather than from the hollow structure alone. Moreover, MnFeO x @YS-ZSM-5 also shows outstanding alkali resistance. After K poisoning, MnFeO x @YS-ZSM-5 maintains high NO x conversion across the mid-temperature range with only minor losses at higher temperatures ( Fig . 2C ). In contrast, pure MnFeO x suffers severe deactivation ( Fig . 2D ), consistent with alkali-induced neutralization of acid sites. MnFeO x /ZSM-5 ( Fig . S43 ) preserves moderate activity at intermediate temperatures but exhibits pronounced high-temperature deterioration, while MnFeO x /S-1 undergoes deactivation over nearly the entire temperature range ( Fig . S44 ), reflecting its limited acidity. Under simultaneous SO 2 and K poisoning, MnFeO x @YS-ZSM-5 uniquely sustains >90% NOₓ conversion at 231 °C ( Fig . S45 ), underscoring its superior multi-poison resistance. Acidity-redox balance and structural stability. Given the central roles of surface acidity and redox properties in NH 3 -SCR 26-28 , NH 3 temperature-programmed desorption (NH 3 -TPD; Figs . 3A , S46 , and Table S6 ) was performed. The results demonstrate that pure MnFeO x possesses the weakest acidity, whereas all MnFeO x -zeolite composites feature enhanced total acidity. MnFeO x @YS-ZSM-5 delivers the highest acidity and the largest proportion of medium-strength acid sites. These medium-strength acid sites are critical for NH 3 adsorption and the dual SCR pathways involving both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms, 20 and correlate well with the superior activity and broad operating window of MnFeO x @YS-ZSM-5 as presented in Fig. 2A . Pyridine infrared (Py-IR; Fig . S47 ) experiment confirms abundant B/L acid sites in zeolite-containing samples and negligible acidity in pure MnFeO x . After K poisoning ( Fig. S48 and Table S6 ), MnFeO x @YS-ZSM-5 retains the highest total acidity, verifying that zeolite encapsulation buffers alkali attack. Hydrogen temperature-programmed reduction (H 2 -TPR; Fig . 3B ) further reveals how zeolite confinement modulates redox behavior. For MnFeO x -zeolite composites, the low-temperature reduction peak (<500 °C, α region) corresponds to Mn 4+ reduction 29 , while the higher-temperature peak (β region) is attributed to Fe 2 O 3 reduction 30 . MnFeO x @YS-ZSM-5 shows higher reduction temperatures in the α region, indicating weaker oxidative capacity. Pure MnFeO x possesses the strongest redox capability, consistent with its highest low-temperature activity but narrow active temperature window ( Fig . 2A ). Zeolite coupling therefore mitigates NH 3 over-oxidation, and synergizes with enhanced acidity to improve high-temperature performance. After K poisoning ( Fig . S49 ), pure MnFeO x shows the most pronounced loss of reducibility, correlating with its severe deactivation ( Fig . 2D ). XPS analysis ( Fig . 3C and Table S7 ) reveals that pure MnFeO x has the highest Mn 4+ fraction (39.6%) 31 , which facilitates NO oxidation to NO 2 and promotes low-temperature fast SCR 32 . Zeolite coupling decreases the Mn 4+ proportion, with MnFeO x @YS-ZSM-5 showing the lowest (29.4%), consistent with its moderated redox behavior. After SO 2 exposure ( Fig . 2B ), the Mn 4+ content of pure MnFeO x ( Fig . S 50 ) decreases sharply, whereas MnFeO x @YS-ZSM-5 ( Fig . 3C ) shows only a slight reduction (29.4%→28.3%). This decrease arises from electron transfer from SO 2 to Mn 4+ 33,34 , leading to sulfate formation and site deactivation. Notably, MnFeO x @YS-ZSM-5 exhibits the lowest surface sulfur content ( Table S7 ), further corroborated by SO 2 -TPD ( Fig . S51 ). After K poisoning ( Fig . S5 2 ), the Mn 4+ fraction in pure MnFeO x decreases markedly, while coupled catalysts remain largely unaffected, explaining their preserved low-temperature activity ( Fig s. 2 C and S43 ). Mn K -edge X-ray absorption near-edge structure (XANES) spectra ( Fig . 3D ) confirm that pure MnFeO x has the highest Mn oxidation state. Zeolite coupling shifts the absorption edge to lower energies, with MnFeO x /ZSM-5 exhibiting a higher Mn valence state than MnFeO x @YS-ZSM-5, consistent with XPS results. After SO 2 poisoning ( Fig. 2B ), both MnFeO x /ZSM-5 and MnFeO x @YS-ZSM-5 exhibit decreased Mn valence ( Fig . 3E ), but the shift is substantially smaller for the yolk-shell catalyst, highlighting the protective role of the zeolite shell. Fourier-transformed (FT) k³ -weighted extended X-ray absorption fine structure (EXAFS; Fig . 3F ) shows shorter Mn-O bond distances in the composite catalysts than in pure MnFeO x , indicative of stronger oxide-zeolite interactions. Wavelet transform analysis ( Fig s. 3G - I ) identifies Mn-O and Mn-Mn/Mn-Fe coordination features 35 , confirming the structural integrity of the encapsulated MnFeO x phase. Reaction pathway and dual-shielding mechanism. To elucidate the NH 3 -SCR reaction pathways, in situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) was conducted at 200 °C. For MnFeO x @YS-ZSM-5, NH 3 adsorption ( Figs. 4A and 4A 1 ) revealed significantly stronger bands for both L acid-bound NH 3 (NH 3 -L) 36 and B acid-bound NH 4 + species (NH 4 + -B) 37,38 compared to pure MnFeO x ( Fig. S53 ), confirming that zeolite encapsulation introduces abundant L and B acid sites, thereby enhancing NH 3 adsorption, consistent with the NH 3 -TPD results. Upon introducing NO + O 2 to pre-adsorbed NH 3 , the NH 3 -L/NH 4 + -B bands on MnFeO x @YS-ZSM-5 decreased gradually without the formation of surface nitrate or nitrite intermediates over 40 min ( Figs. 4B and 4B 1 ). In contrast, pure MnFeO x ( Fig. S54 ) showed rapid consumption of NH 3 -L species 39 and immediate accumulation of monodentate nitrate 40 and bridged nitrate 41 . Consistently, NO + O 2 adsorption experiments on MnFeO x @YS-ZSM-5 ( Fig. 4C ) produced virtually no surface nitrogen species over 40 min, except for a weak transient NO 2 band 42 that disappears upon N 2 purging, unlike pure MnFeO x , which formed substantial nitrates/nitrites ( Fig. S55 ). These results demonstrate that the NH 3 -SCR reaction over MnFeO x @YS-ZSM-5 predominantly follows the E-R mechanism, involving gaseous NO reacting directly with adsorbed NH 3 species. Conversely, pure MnFeO x primarily proceeds via a L-H pathway involving surface nitrate intermediates ( Fig. S56 ), and this mechanistic divergence is further supported by NO-TPD observations ( Fig. S57 ). The substantially stronger oxidative capability of pure MnFeO x , as evidenced by H 2 -TPR, XPS, and XAFS analyses, facilitates NO oxidation to NO 2 and enables the “fast SCR” pathway at low temperatures, yet simultaneously promotes nitrate accumulation, NH 4 NO 3 decomposition, and the formation of undesired N 2 O. In contrast, zeolite encapsulation attenuates NO adsorption and oxidation, suppresses nitrate/nitrite formation, and thereby enhances N 2 selectivity across a broad temperature range. Density functional theory (DFT) calculations further support these findings. As shown in Figs. 4D - G and S58 - S59 , NO adsorption on Mn and Fe sites of pure MnFeO x is strong, with adsorption energies ( E ads ) of −2.607 eV (Mn, Fig. 4D ) and −4.100 eV (Fe, Fig. 4E ), respectively. In contrast, NO adsorption on MnFeO x @YS-ZSM-5 is significantly weakened, with corresponding E ads of −1.686 eV (Mn, Fig. 4F ) and −2.971 eV (Fe, Fig. 4G ), consistent with the experimentally observed suppression of surface nitrate formation. The adsorption behavior of SO 2 was further examined by DFT calculations ( Figs. 5A - D ). Relative to pure MnFeO x , SO 2 adsorption on MnFeO x @YS-ZSM-5 is substantially weakened, accompanied by elongated S-Mn and S-Fe bond lengths. Remarkably, SO 2 adsorption on Fe sites becomes thermodynamically unfavorable ( E ads = +0.383 eV), indicating that the zeolite shell effectively suppresses SO 2 binding. Moreover, SO 2 adsorption on B acid sites of ZSM-5 is also unfavorable ( E ads = +0.496 eV; Fig. S60 ), reflecting electrostatic repulsion that further inhibits sulfur uptake. To directly probe the structural stability of active sites under SO 2 exposure, in situ EXAFS measurements were performed during transient SO 2 + O 2 treatment at 246 °C (consistent with the temperature used in the SO 2 resistance test shown in Fig. 2B). As shown in Fig. 5E , the Mn K -edge XANES profiles of MnFeO x @YS-ZSM-5 remain essentially unchanged after 2-3 h of SO 2 + O 2 exposure. Correspondingly, the Mn-O peak position in Fourier-transform EXAFS spectra ( Fig. S61 ) and the Mn-O coordination number (~4.9), as well as the bond distance (~1.91 Å) ( Figs. 5F - H ) show negligible variation, confirming that SO 2 does not significantly interact with or perturb the encapsulated MnFeO x active sites. Collectively, these results establish a dual-shielding mechanism for SO 2 resistance in the yolk-shell MnFeO x @YS-ZSM-5 nanoreactor ( Fig. 5I ). The crystalline ZSM-5 shell physically isolates the MnFeO x core from direct sulfur attack, while its B acid sites electrostatically repel SO 2 and suppress its adsorption. This synergistic physical and chemical shielding not only preserves the structural integrity of the active phase but also enforces an E-R reaction pathway, thereby underpinning the remarkable activity, selectivity, and durability of the nanoreactor under harsh, multi-poisoning SCR conditions. Discussion In summary, we successfully realize the nanoreactor concept for NO x reduction by constructing a yolk-shell MnFeO x @YS-ZSM-5 catalyst that addresses the long-standing challenge of simultaneous SO 2 and alkali poisoning in NH 3 -SCR. While the synergistic coupling of zeolites and metal oxides has been extensively explored to mitigate deactivation, previous approaches, largely limited to simple mixing or impregnation, failed to achieve both high redox-site content and effective protection. We overcome this limitation through an impregnation-dissolution-recrystallization strategy that enables the confinement of high-content (>10 wt.%) MnFeO x nanoparticles within a hollow ZSM-5 single-crystal shell, yielding a robust yolk-shell nanoreactor with preserved zeolite framework integrity. This architecture reveals a synergistic dual-shielding mechanism governing its superior poisoning resistance: the ZSM-5 shell physically hinders the MnFeO x core from being directly exposed to SO 2 , whereas its abundant external Brønsted acid sites provide chemical shielding by preferentially adsorbing alkali metal and suppressing SO 2 adsorption. This synergistic protection delivers >90% NO x conversion with high N 2 selectivity under simultaneous SO 2 and K poisoning. The strategy further demonstrates broad versatility, extending successfully to other mixed metal oxides such as MnCoO x and MnCeO x . By establishing this yolk-shell architecture as a general platform, our work introduces a powerful paradigm for engineering durable SCR catalysts. More broadly, the hollow zeolite-confined nanoreactor concept opens new avenues for robust catalysts in emission control and other high-temperature environmental processes requiring long-term stability against complex poisons. Methods Catalyst synthesis The yolk-shell MnFeO x @YS-ZSM-5 catalyst was synthesized by an impregnation-dissolution-recrystallization (IDR) strategy. For comparison, MnFeO x metal oxides supported on the outer surface of ZSM-5 was prepared by the conventional impregnation method. To reveal the formation mechanism of MnFeO x @YS-ZSM-5, the samples crystallized at each step were collected. Furthermore, to verify the universality of the IDR method, ZSM-5 zeolite confining other metal active sites were also prepared. The detailed preparation procedures are discussed in the Supplementary Information. Characterization methods Various testing methods—including X-ray diffraction (XRD), N 2 adsorption/desorption analysis, X-ray photoelectron spectroscopy (XPS), pyridine infrared (Py-IR), NH 3 temperature-programmed desorption (NH 3 -TPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM (HRTEM), energy-dispersive X-ray spectroscopy (EDS) elemental mapping, aberration-corrected TEM (AC-TEM), AC-EDS elemental mapping, X-ray absorption near-edge structure (XANES), in situ extended X-ray absorption fine structure ( in situ EXAFS), density functional theory (DFT) calculations, and the in situ diffuse reflectance infrared Fourier-transform spectroscopy ( in situ DRIFTS)—were adopted to measure the physical and chemical properties and elucidate the plausible reaction mechanism over the yolk-shell MnFeO x @YS-ZSM-5 and related samples. The detailed measuring processes are described in the Supplementary Information. Activity and kinetic tests The detailed NH 3 -SCR activity and kinetic tests are also presented in the Supplementary Information. Declarations Data availability The additional data are provided in the Supplementary Information. All the data that support the findings of this study are available from the corresponding author upon reasonable request. Acknowledgements This work was supported by the National Natural Science Foundation of China (22476078, 22376222, 22276086 and 22306086), National key R&D Program of China (2023YFA1508400 and 2024YFC3712104), the Natural Science Foundation of Jiangxi Province (20243BCE51169, 20232BCJ22003, 20232BAB213028 and 20242BAB25144), Science and Technology Innovation Program of Hunan Province (2023RC1012), Central South University Research Program of Advanced Interdisciplinary Studies (Grant 2023QYJC012) and the Natural Science Foundation of Chongqing (CSTB2023NSCQ-MSX0950, CSTB2024NSCQ-MSX1295), all of which are greatly acknowledged by the authors. Author contributions H. Peng conceived the research idea, designed the experiments, and supervised this project, wrote-review & edited the manuscript. Y. Li performed the experiments, analyzed the data, and wrote the manuscript. G. Li performed the DFT calculations. R. Li took part in the synthesis of samples and characterizations. M. Liu commented on the manuscript and wrote-review & edited the manuscript. J. Ji, X. Hu, F. Yu, H. Li, and W. Liu discussed the results and commented on the manuscript. Competing interests The authors declare no competing financial interests. References Li, Z. et al. Unexpected Redox Role of WO 3 in V 2 O 5 -WO 3 /TiO 2 Catalysts for Selective Reduction of NO by Forming V–W Dinuclear Sites. Angew. Chem. Int. Ed . 64 , e202501957 (2025). Shan, Y. et al. Strikingly distinctive NH 3 -SCR behavior over Cu-SSZ-13 in the presence of NO 2 . Nat. Commun. 13 , 4606 (2022). Liu, G. et al. 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ACS Catal. 10 , 9034-9045 (2020). Liu, Z. et al. Fe-Doped Mn 3 O 4 Spinel Nanoparticles with Highly Exposed Feoct–O–Mntet Sites for Efficient Selective Catalytic Reduction (SCR) of NO with Ammonia at Low Temperatures. ACS Catal. 10 , 6803-6809 (2020). Li, L. et al. Highly Efficient RuO x /NbO x -ZrO x Catalysts for Ammonia Removal via Tuning Acidic Active Species. ACS Sustain. Chem. Eng. 11 , 17015-17030 (2023). Ma, S. et al. Effect of W on the acidity and redox performance of the Cu 0.02 Fe 0.2 WTiO x (a = 0.01, 0.02, 0.03) catalysts for NH 3 -SCR of NO. Appl. Catal. B: Environ. Energy 248 , 226-238 (2019). Wang, P. et al. Poisoning-Resistant NO x Reduction in the Presence of Alkaline and Heavy Metals over H-SAPO-34-Supported Ce-Promoted Cu-Based Catalysts. Environ. Sci. Technol. 54 , 6396-6405 (2020). Wang, Z. et al. The superior performance of CoMnO x catalyst with ball-flowerlike structure for low-temperature selective catalytic reduction of NO x by NH 3 . Chem. Eng. 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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-9293985","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":620973463,"identity":"7f13d8d2-b4d0-4790-955e-d927f1d5171c","order_by":0,"name":"Honggen Peng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7ElEQVRIiWNgGAWjYJACZijN+ABCJxCvhdmAZC1sEkRpMWfvPfy6oOKO3Xz33mPVBTWHGfjZcwwYfu7ArcWy51ya9Ywzz5I3njmXdnvGscMMkj1vDBh7z+DWYnAjx8yYt+1wsuGMHLPbvA2HQSIGzIxteLTcfwPVMv+NWTFIiz1BLTd4jB8DtdjJS/CYMYNtkSCgxbInx4yZ58zhBAOeHGNpnmPpPBJnnhUc7MWjxZz9jPFnnorD9vLtZww/89RYy/G3J2988BOfw6DRkbjhAESAB0QcwK0BrIX5A5C2l2/Ap2wUjIJRMApGNAAA3UxPd//maYcAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0001-9133-5727","institution":"Nanchang University","correspondingAuthor":true,"prefix":"","firstName":"Honggen","middleName":"","lastName":"Peng","suffix":""},{"id":620973464,"identity":"a5d82061-6e74-44a4-93ad-b7b8266df490","order_by":1,"name":"Yonglong Li","email":"","orcid":"","institution":"Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Yonglong","middleName":"","lastName":"Li","suffix":""},{"id":620973465,"identity":"f4e54eb7-31f4-4b71-a1e0-b125ffa5bc90","order_by":2,"name":"Guobo Li","email":"","orcid":"","institution":"Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Guobo","middleName":"","lastName":"Li","suffix":""},{"id":620973466,"identity":"0528d6d8-a70e-41c3-beaa-a24ffc8c18de","order_by":3,"name":"Rongxing Li","email":"","orcid":"","institution":"Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Rongxing","middleName":"","lastName":"Li","suffix":""},{"id":620973467,"identity":"7c7823af-a3ea-4c78-8675-b4756341a0ca","order_by":4,"name":"Jian Ji","email":"","orcid":"","institution":"Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Jian","middleName":"","lastName":"Ji","suffix":""},{"id":620973468,"identity":"99bc7a93-e5c7-4128-9092-1a444078529b","order_by":5,"name":"Xiaonan Hu","email":"","orcid":"","institution":"Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Xiaonan","middleName":"","lastName":"Hu","suffix":""},{"id":620973469,"identity":"33bbab96-fe30-4343-8880-3040613ba15d","order_by":6,"name":"Fengbo Yu","email":"","orcid":"","institution":"Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Fengbo","middleName":"","lastName":"Yu","suffix":""},{"id":620973470,"identity":"87e86c7d-2b55-4fa2-b057-33a3ba91d8b7","order_by":7,"name":"Wenming Liu","email":"","orcid":"","institution":"Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Wenming","middleName":"","lastName":"Liu","suffix":""},{"id":620973471,"identity":"d131684f-6742-4f17-a0ec-8af4993548d0","order_by":8,"name":"Hongmei Li","email":"","orcid":"","institution":"Central South University","correspondingAuthor":false,"prefix":"","firstName":"Hongmei","middleName":"","lastName":"Li","suffix":""},{"id":620973472,"identity":"a3eef314-58f6-476e-a113-ed4cbd7b74ea","order_by":9,"name":"Min Liu","email":"","orcid":"https://orcid.org/0000-0002-9007-4817","institution":"Central South University","correspondingAuthor":false,"prefix":"","firstName":"Min","middleName":"","lastName":"Liu","suffix":""}],"badges":[],"createdAt":"2026-04-01 15:41:01","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9293985/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9293985/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106887050,"identity":"b8211df7-9010-49ea-b187-d823e7096b78","added_by":"auto","created_at":"2026-04-14 12:47:43","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":911411,"visible":true,"origin":"","legend":"\u003cp\u003eMorphological and structural characterizations. (A) Schematic illustration for the synthesis of the yolk-shell structured MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 nanoreactor via the IDR method. (B, C) TEM images, (D) HAADF-STEM image, (E, F) EDS elemental mappings and (G, H) iDPC images of the yolk-shell structured MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 nanoreactor. (I) N\u003csub\u003e2\u003c/sub\u003e adsorption-desorption isotherms of ZSM-5, MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5, and MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 samples. (J) Mn 2p and Fe 2p XPS spectra of the MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5 and MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 samples.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9293985/v1/02bac87a429db8a8e717db6c.png"},{"id":106961944,"identity":"6b1157ec-8b03-4959-8db3-41586eb064a4","added_by":"auto","created_at":"2026-04-15 09:28:01","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":285636,"visible":true,"origin":"","legend":"\u003cp\u003eNH\u003csub\u003e3\u003c/sub\u003e-SCR catalytic performance.\u003cstrong\u003e \u003c/strong\u003e(A) NO\u003csub\u003ex\u003c/sub\u003e conversion as a function of temperature in NH\u003csub\u003e3\u003c/sub\u003e-SCR reaction over the MnFeO\u003csub\u003ex\u003c/sub\u003e, MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5, MnFeO\u003csub\u003ex\u003c/sub\u003e/S-1, and MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalysts. (B) SO\u003csub\u003e2\u003c/sub\u003e resistance performance over the MnFeO\u003csub\u003ex\u003c/sub\u003e, MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5, and MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalysts at 246 °C. (C and D) NO\u003csub\u003ex\u003c/sub\u003e conversion as a function of temperature in NH\u003csub\u003e3\u003c/sub\u003e-SCR reaction over the K-poisoned and fresh catalysts. Reaction conditions: 500 ppm NO, 500 ppm NH\u003csub\u003e3\u003c/sub\u003e, 5 vol.% O\u003csub\u003e2\u003c/sub\u003e, 5 vol.% H\u003csub\u003e2\u003c/sub\u003eO, 50 ppm SO\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e \u003c/sup\u003e(when used), balance N\u003csub\u003e2\u003c/sub\u003e, WHSV = 60000 mL g\u003csub\u003ecat.\u003c/sub\u003e\u003csup\u003e−1\u003c/sup\u003e h\u003csup\u003e−1\u003c/sup\u003e.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9293985/v1/a87805ecd955785e3909d23c.png"},{"id":106887052,"identity":"bd92061e-abda-4d32-9516-06ec97f89bef","added_by":"auto","created_at":"2026-04-14 12:47:43","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":183468,"visible":true,"origin":"","legend":"\u003cp\u003ePhysicochemical characterizations and analysis.\u003cstrong\u003e \u003c/strong\u003e(A) NH\u003csub\u003e3\u003c/sub\u003e-TPD curves and (B) H\u003csub\u003e2\u003c/sub\u003e-TPR profiles over the MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 and related samples. (C) Mn 2p XPS spectra over the fresh and related SO\u003csub\u003e2\u003c/sub\u003e-poisoned samples. (D and E) Mn \u003cem\u003eK\u003c/em\u003e-edge XANES spectra and (F) FTs of Mn \u003cem\u003eK\u003c/em\u003e-edge EXAFS oscillations for fresh and corresponding SO\u003csub\u003e2\u003c/sub\u003e-poisoning samples. (G-I) WT plots for EXAFS spectra over the MnFeO\u003csub\u003ex\u003c/sub\u003e, MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5, and MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-9293985/v1/2500dafb9eb998a44346a9c0.png"},{"id":106960452,"identity":"01529f00-a9d5-4b32-86dd-37994c8e90d4","added_by":"auto","created_at":"2026-04-15 09:21:12","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":409034,"visible":true,"origin":"","legend":"\u003cp\u003eStudy on the mechanism of catalytic reaction. (A and A\u003csub\u003e1\u003c/sub\u003e)\u003cem\u003e In situ\u003c/em\u003e DRIFT spectra of NH\u003csub\u003e3\u003c/sub\u003e adsorption on MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalyst at 200 °C. (B and B\u003csub\u003e1\u003c/sub\u003e) \u003cem\u003eIn situ\u003c/em\u003e DRIFT spectra of pre-adsorbed NH\u003csub\u003e3\u003c/sub\u003e species reacted with NO + O\u003csub\u003e2\u003c/sub\u003e on MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalyst at 200 °C; (C) \u003cem\u003eIn situ \u003c/em\u003eDRIFT spectra of NO + O\u003csub\u003e2\u003c/sub\u003e adsorption on MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalyst at 200 °C; Optimized adsorption configurations of NO gas molecules on (D and E) MnFeO\u003csub\u003ex\u003c/sub\u003e and (F and G) MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 samples.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-9293985/v1/714f442fd97ef2639e316054.png"},{"id":106887055,"identity":"0ecb2a62-e03b-404f-9e9c-3b7d41e3351c","added_by":"auto","created_at":"2026-04-14 12:47:43","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":387583,"visible":true,"origin":"","legend":"\u003cp\u003eStructure-activity relationship analysis. Optimized adsorption configurations of SO\u003csub\u003e2\u003c/sub\u003e gas molecules on (A and B) MnFeO\u003csub\u003ex\u003c/sub\u003e and (C and D) MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalysts. (E) \u003cem\u003eIn situ\u003c/em\u003e Mn \u003cem\u003eK\u003c/em\u003e-edge XANES spectra of the transient reaction on MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalyst after 0, 2, and 3 h treatment at 246 °C in 250 ppm SO\u003csub\u003e2\u003c/sub\u003e + 5 vol.% O\u003csub\u003e2\u003c/sub\u003e atmosphere. WT plots for EXAFS spectra of MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalyst after being treated at 246 °C in an atmosphere of 250 ppm SO\u003csub\u003e2\u003c/sub\u003e + 5 vol.% O\u003csub\u003e2\u003c/sub\u003e for (F) 0 h, (G) 2 h, and (H) 3 h (R\u003cem\u003e \u003c/em\u003eand CN denote the average interatomic distances between Mn and the O atoms in the first coordination shell and the Mn-O coordination number, respectively). (I) Schematic diagram of enhanced SO\u003csub\u003e2\u003c/sub\u003e poisoning resistance of the catalyst through combined physical shielding and chemical repulsion effects.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-9293985/v1/19ade99335d855aa744a026a.png"},{"id":106963348,"identity":"40862879-44b2-4eeb-85e0-d615ec0d1407","added_by":"auto","created_at":"2026-04-15 09:43:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3101196,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9293985/v1/1c293aeb-6b6b-4b30-b70b-8b802ea18a1b.pdf"},{"id":106961937,"identity":"45221018-00e7-4c0b-989a-f00877ad2664","added_by":"auto","created_at":"2026-04-15 09:27:53","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":48159646,"visible":true,"origin":"","legend":"Supplementary Information","description":"","filename":"SupplementaryInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-9293985/v1/cca177a98371fedef97a7f73.docx"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eYolk-Shell Zeolite Nanoreactors Enable Multi‑Poison Resistance for NO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003ex\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e Reduction\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe abatement of nitrogen oxides (NO\u003csub\u003ex\u003c/sub\u003e) from industrial stationary sources (coal-fired power plants and waste incinerators, etc.) remains a critical environmental challenge due to their severe impact on air quality and human health\u003csup\u003e1-4\u003c/sup\u003e. Ammonia selective catalytic reduction (NH\u003csub\u003e3\u003c/sub\u003e-SCR) is currently one of the most efficient industrial technologies for NO\u003csub\u003ex\u003c/sub\u003e removal\u003csup\u003e5-7\u003c/sup\u003e. However, the practical longevity of SCR catalysts is severely compromised in real-world flue gas environments, where NO\u003csub\u003ex\u003c/sub\u003e coexists with potent poisons such as sulfur dioxide (SO\u003csub\u003e2\u003c/sub\u003e) and alkali metal (e.g., K\u003csub\u003e2\u003c/sub\u003eO)\u003csup\u003e8,9\u003c/sup\u003e. These poisons cause rapid and serious deactivation, making the development of catalysts with simultaneous resistance to SO\u003csub\u003e2\u003c/sub\u003e and alkali poisoning a paramount challenge for sustainable industrial operation\u003csup\u003e10-13\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eCoupling zeolites with transition-metal oxides has emerged as a promising approach because these components offer complementary functionalities\u003csup\u003e14-17\u003c/sup\u003e. Zeolites, such as ZSM-5, provide high surface area and Br\u0026oslash;nsted acidity capable of neutralizing alkali metal, whereas metal oxides (e.g., MnO\u003csub\u003ex\u003c/sub\u003e, FeO\u003csub\u003ex\u003c/sub\u003e, CeO\u003csub\u003ex\u003c/sub\u003e) supply the redox activity required for SCR\u003csup\u003e18-20\u003c/sup\u003e. Yet conventional integration strategies (e.g., simple mixing, deposition, or impregnation)\u003csup\u003e16,17,21,22\u003c/sup\u003e leave oxide nanoparticles exposed on the external surface of the zeolite, making them vulnerable to sulfation and alkali poisoning, even when the oxide loading is increased\u003csup\u003e23,24\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eTo overcome this limitation, we envisioned a different architectural strategy: constructing a zeolite nanoreactor in which a high-content redox-active oxide core is encapsulated inside a porous acidic shell. In such a configuration, the zeolite shell would not merely confine the catalyst but actively regulate its interaction with the environment, allowing reactants to diffuse inward while intercepting poisons before they reach the active phase. This confined architecture could enable simultaneous preservation of high redox-site content and strong resistance to multi-component poisoning. We realize this concept by synthesizing a yolk-shell MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalyst through an impregnation-dissolution-recrystallization (IDR) strategy. The resulting nanoreactor consists of MnFeO\u003csub\u003ex\u003c/sub\u003e nanoparticles confined within a hollow single-crystalline ZSM-5 shell. Structural characterization, operando spectroscopy, and theory collectively reveal a dual-shielding mechanism combining physical isolation and chemical adsorption control. This architecture delivers outstanding SCR activity and stability under simultaneous SO\u003csub\u003e2\u003c/sub\u003e and alkali exposure and can be generalized to other mixed-metal oxides, establishing hollow zeolite nanoreactors as a new platform for durable NO\u003csub\u003ex\u003c/sub\u003e emission-control catalysis.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eFormation of the yolk\u003c/strong\u003e\u003cstrong\u003e-\u003c/strong\u003e\u003cstrong\u003eshell nanoreactor.\u003c/strong\u003e The yolk-shell MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 nanoreactor was synthesized via an IDR strategy (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;1A\u003c/strong\u003e). In this architecture, crystalline ZSM-5 forms\u0026nbsp;a hollow\u0026nbsp;shell, while MnFeO\u003csub\u003ex\u003c/sub\u003e nanoparticles are confined as an internal yolk. Bulk ZSM-5 is first impregnated with Mn and Fe precursors and calcined to generate MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5,\u0026nbsp;in which metal oxide are dispersed on the zeolite external surface. Subsequent hydrothermal treatment in tetrapropylammonium hydroxide (TPAOH) induces selective internal dissolution of the zeolite and simultaneous recrystallization at the exterior, ultimately yielding a hollow ZSM-5 shell that fully encapsulates the MnFeO\u003csub\u003ex\u003c/sub\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003enanoparticles.\u003c/p\u003e\n\u003cp\u003eElectron microscopy reveals a clear structural evolution during this process. Pristine ZSM-5 consists of well-defined blocky crystals with sharp edges and an average particle size of ~145\u0026thinsp;nm\u0026nbsp;(\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003es.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S1\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eand \u003cstrong\u003eS2\u003c/strong\u003e). After impregnation, MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5 retains the original morphology\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e(\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S3\u003c/strong\u003e), but transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS; \u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS4\u003c/strong\u003e) mapping confirm that Mn and Fe species are distributed on the external surface.\u0026nbsp;In contrast,\u0026nbsp;the final\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 nanoreactor exhibits a distinct yolk-shell architecture. Scanning electron microscopy (SEM) shows hollow cubic particles (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S5\u003c/strong\u003e), while TEM (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003es.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;1B\u003c/strong\u003e, \u003cstrong\u003e1C\u003c/strong\u003e,\u0026nbsp;and\u003cstrong\u003e\u0026nbsp;S6\u003c/strong\u003e)\u0026nbsp;and high-angle annular dark-field scanning TEM (HAADF-STEM) image\u0026nbsp;(\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e1D\u003c/strong\u003e)\u0026nbsp;unambiguously demonstrate that MnFeO\u003csub\u003ex\u003c/sub\u003e nanoparticles are confined within the internal cavity of hollow ZSM-5, with no detectable species on the outer surface. The nanoreactors maintain an average size of ~145 nm, with shell thicknesses ranging from ~10 to ~30 nm. Notably, the MnFeO\u003csub\u003ex\u003c/sub\u003e nanoparticles are preferentially located near the inner shell surface rather than at the geometric center. EDS elemental mappings (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003es.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;1E\u003c/strong\u003e and \u003cstrong\u003e1F\u003c/strong\u003e) and line-scan profiles (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S7\u003c/strong\u003e) confirm\u0026nbsp;that\u0026nbsp;Mn and Fe\u0026nbsp;are spatially confined inside the zeolite shell rather than on\u0026nbsp;the external surface. Integrated differential phase-contrast STEM (iDPC-STEM)\u0026nbsp;(\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003es.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;1G\u003c/strong\u003e and \u003cstrong\u003eS8\u003c/strong\u003e) directly resolves the atomic-scale MFI framework of the ZSM-5 shell while simultaneously visualizing the encapsulated MnFeO\u003csub\u003ex\u003c/sub\u003e yolk. The corresponding Fourier transform pattern (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S8F\u003c/strong\u003e) reveals a well-ordered diffraction spot array, confirming the single-crystalline nature of the zeolite shell. Given that the zeolite micropores (~0.54 nm\u003cstrong\u003e,\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e1H\u003c/strong\u003e) are much smaller than the MnFeO\u003csub\u003ex\u003c/sub\u003e nanoparticles (~8.73 nm), migration of the active phase into the zeolite channels is effectively prohibited.\u003c/p\u003e\n\u003cp\u003eNitrogen adsorption-desorption results (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003es.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;1I\u003c/strong\u003e and\u003cstrong\u003e\u0026nbsp;Fig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S9\u003c/strong\u003e)\u0026nbsp;confirm the hollow structure of MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5, as evidenced by its distinctive H2-type hysteresis loop and increased total pore volume (\u003cstrong\u003eTable S1\u003c/strong\u003e)\u003csup\u003e25\u003c/sup\u003e. XRD analysis\u0026nbsp;(\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS10\u003c/strong\u003e)\u0026nbsp;verifies that the ZSM-5 zeolite retains its MFI crystal structure without loss of crystallinity after the encapsulation process. Meanwhile, the strong attenuation of\u0026nbsp;Fe 2p and Mn 2p\u0026nbsp;signals in the X-ray photoelectron spectroscopy (XPS) spectra\u0026nbsp;(\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;1J\u003c/strong\u003e)\u0026nbsp;of MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 provides further evidence consistent with the successful confinement of the MnFeO\u003csub\u003ex\u003c/sub\u003e metal oxide core within the zeolite shell. Time-dependent hydrothermal treatments reveal the mechanism underlying yolk-shell formation. Progressive development of internal voids is observed with increasing treatment duration, as evidenced by microscopy (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003es.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S11\u003c/strong\u003e-\u003cstrong\u003eS1\u003c/strong\u003e\u003cstrong\u003e7\u003c/strong\u003e)\u0026nbsp;and\u0026nbsp;N\u003csub\u003e2\u003c/sub\u003e adsorption-desorption results (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S1\u003c/strong\u003e\u003cstrong\u003e8)\u003c/strong\u003e, while XRD patterns (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS19\u003c/strong\u003e)\u0026nbsp;confirm that the MFI framework is preserved throughout the process. XPS\u0026nbsp;results\u0026nbsp;(\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S\u003c/strong\u003e\u003cstrong\u003e20\u003c/strong\u003e)\u0026nbsp;show pronounced Si enrichment and Al depletion on the external surface after TPAOH hydrothermal treatment, indicative of preferential internal\u0026nbsp;Si\u0026nbsp;dissolution and outward recrystallization of silicate species (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S21\u003c/strong\u003e)\u003csup\u003e25\u003c/sup\u003e.\u0026nbsp;The universality\u0026nbsp;of the IDR strategy is further demonstrated through the successful synthesis of hollow ZSM-5 zeolite encapsulating MnCoO\u003csub\u003ex\u003c/sub\u003e or MnCeO\u003csub\u003ex\u003c/sub\u003e (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003es.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S22\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eand \u003cstrong\u003eS23\u003c/strong\u003e). Both systems display well-defined yolk-shell architectures, as evidenced by adsorption-desorption profiles (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003es.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S24\u003c/strong\u003e and \u003cstrong\u003eS25\u003c/strong\u003e) and XRD patterns (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS26\u003c/strong\u003e), confirming that the zeolite crystallinity remains intact regardless of the metal oxide precursor.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNH\u003csub\u003e3\u003c/sub\u003e-SCR performance and\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003emulti-poison resistance\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e To clarify the catalytic advantages of the yolk-shell MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 nanoreactor in NH\u003csub\u003e3\u003c/sub\u003e-SCR (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003cstrong\u003eA\u003c/strong\u003e), comparative catalysts (MnFeO\u003csub\u003ex\u003c/sub\u003e, MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5, and MnFeO\u003csub\u003ex\u003c/sub\u003e/S-1; the S-1 support is an aluminum-free zeolite with much weaker acidity than ZSM-5) were prepared (\u003cstrong\u003eFigs. S27\u003c/strong\u003e-\u003cstrong\u003eS32\u003c/strong\u003e; \u003cstrong\u003eTable S1\u003c/strong\u003e) and then evaluated. Pure MnFeO\u003csub\u003ex\u003c/sub\u003e shows high activity only below 200 \u0026deg;C, followed by rapid deactivation due to excessive NH\u003csub\u003e3\u003c/sub\u003e oxidation (\u003cstrong\u003eFig. S33\u003c/strong\u003e) and poor N\u003csub\u003e2\u003c/sub\u003e selectivity (\u003cstrong\u003eFig. S34\u003c/strong\u003e). Coupling MnFeO\u003csub\u003ex\u003c/sub\u003e with a zeolite broadens the operational window. Notably, MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 delivers the most robust performance, maintaining \u0026gt;80% NOₓ conversion across a wide temperature range of 220-500 \u0026deg;C, while MnFeO\u003csub\u003ex\u003c/sub\u003e/S-1 and MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5 display significantly compromised medium-high-temperature performance. Samples treated hydrothermally in TPAOH for different durations (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS35\u003c/strong\u003e) all retain similarly wide temperature windows. Compared with reported MnFeO\u003csub\u003ex\u003c/sub\u003e-based\u0026nbsp;catalysts (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS36\u003c/strong\u003e and \u003cstrong\u003eTable S2\u003c/strong\u003e), MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 exhibits a remarkably broader operational range. Kinetic analysis (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S37\u003c/strong\u003e and\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eTables S3\u003c/strong\u003e-\u003cstrong\u003eS5\u003c/strong\u003e) shows that all oxide-zeolite composites possess substantially lower apparent activation energies than pure MnFeO\u003csub\u003ex\u003c/sub\u003e.\u003c/p\u003e\n\u003cp\u003eThe SO\u003csub\u003e2\u003c/sub\u003e tolerance was evaluated at 246 \u0026deg;C with 50 ppm SO\u003csub\u003e2\u003c/sub\u003e (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e2B\u003c/strong\u003e). MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5 undergoes rapid deactivation, with NOₓ conversion dropping from 98% to 33% within 0.5 h and stabilizing below 39% after SO\u003csub\u003e2\u003c/sub\u003e was cut off. Pure MnFeO\u003csub\u003ex\u003c/sub\u003e shows only transient resistance before severe deterioration. In striking contrast, MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 stabilizes at ~83% conversion and rapidly recovers to ~90% once SO\u003csub\u003e2\u003c/sub\u003e is removed, demonstrating largely reversible deactivation. Pre-sulfidation experiments (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS38\u003c/strong\u003e) further confirm the\u0026nbsp;better\u0026nbsp;SO\u003csub\u003e2\u003c/sub\u003e resistance of the yolk-shell nanoreactor. To decouple the effects of hollow morphology from encapsulation, a control catalyst consisting of MnFeO\u003csub\u003ex\u003c/sub\u003e supported on hollow ZSM-5 (MnFeO\u003csub\u003ex\u003c/sub\u003e/Hollow-ZSM-5) was synthesized (\u003cstrong\u003eFigs\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S39\u003c/strong\u003e-\u003cstrong\u003eS40\u003c/strong\u003e). Although this catalyst exhibits comparable SCR activity (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS41\u003c/strong\u003e), its SO\u003csub\u003e2\u003c/sub\u003e tolerance is markedly inferior (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS42\u003c/strong\u003e), establishing that the superior durability of MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 arises from the dual-shielding effect of the intact zeolite shell\u0026nbsp;(physical\u0026nbsp;protection\u0026nbsp;of MnFeO\u003csub\u003ex\u003c/sub\u003e from SO\u003csub\u003e2\u003c/sub\u003e and chemical regulation of surface adsorption) rather than from the hollow structure alone. Moreover, MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 also shows outstanding alkali resistance. After K poisoning,\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 maintains high NO\u003csub\u003ex\u003c/sub\u003e conversion across the mid-temperature range with only minor losses at higher temperatures (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;2C\u003c/strong\u003e).\u0026nbsp;In contrast, pure MnFeO\u003csub\u003ex\u003c/sub\u003e suffers severe deactivation (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;2D\u003c/strong\u003e), consistent with alkali-induced neutralization of acid sites. MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5 (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S43\u003c/strong\u003e) preserves moderate activity at intermediate temperatures but exhibits pronounced high-temperature deterioration, while MnFeO\u003csub\u003ex\u003c/sub\u003e/S-1 undergoes deactivation over nearly the entire temperature range (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S44\u003c/strong\u003e),\u0026nbsp;reflecting its limited acidity. Under simultaneous SO\u003csub\u003e2\u003c/sub\u003e and K poisoning, MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 uniquely sustains \u0026gt;90% NOₓ conversion at 231 \u0026deg;C (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S45\u003c/strong\u003e), underscoring its\u0026nbsp;superior\u0026nbsp;multi-poison resistance.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcidity-redox balance and structural stability.\u0026nbsp;\u003c/strong\u003eGiven the central roles of surface acidity and redox properties in NH\u003csub\u003e3\u003c/sub\u003e-SCR\u003csup\u003e26-28\u003c/sup\u003e, NH\u003csub\u003e3\u003c/sub\u003e temperature-programmed desorption (NH\u003csub\u003e3\u003c/sub\u003e-TPD; \u003cstrong\u003eFigs\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;3A\u003c/strong\u003e, \u003cstrong\u003eS46\u003c/strong\u003e, and \u003cstrong\u003eTable S6\u003c/strong\u003e) was performed.\u0026nbsp;The results demonstrate that pure\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e possesses the weakest acidity, whereas all MnFeO\u003csub\u003ex\u003c/sub\u003e-zeolite composites feature enhanced total acidity.\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 delivers the highest acidity and the largest proportion of medium-strength acid sites. These medium-strength acid sites are critical for NH\u003csub\u003e3\u003c/sub\u003e adsorption and the dual SCR pathways involving both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms,\u003csup\u003e20\u003c/sup\u003e and correlate well with the superior activity and broad operating window of MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 as presented in \u003cstrong\u003eFig. 2A\u003c/strong\u003e. Pyridine infrared (Py-IR; \u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S47\u003c/strong\u003e)\u0026nbsp;experiment confirms abundant B/L acid sites in zeolite-containing samples and negligible acidity in pure\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e. After K poisoning (\u003cstrong\u003eFig. S48\u003c/strong\u003e and \u003cstrong\u003eTable S6\u003c/strong\u003e),\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 retains the highest total acidity, verifying that zeolite encapsulation buffers alkali attack.\u0026nbsp;Hydrogen temperature-programmed reduction (H\u003csub\u003e2\u003c/sub\u003e-TPR; \u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;3B\u003c/strong\u003e) further reveals how zeolite confinement modulates redox behavior.\u0026nbsp;For MnFeO\u003csub\u003ex\u003c/sub\u003e-zeolite composites, the low-temperature reduction peak (\u0026lt;500\u0026thinsp;\u0026nbsp;\u0026deg;C,\u0026nbsp;\u0026alpha;\u0026nbsp;region) corresponds to Mn\u003csup\u003e4+\u003c/sup\u003e\u003csup\u003e\u0026nbsp;\u003c/sup\u003ereduction\u003csup\u003e29\u003c/sup\u003e, while the higher-temperature peak (\u0026beta; region) is attributed to Fe\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e reduction\u003csup\u003e30\u003c/sup\u003e. MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 shows higher reduction temperatures in the \u0026alpha; region, indicating weaker oxidative capacity. Pure MnFeO\u003csub\u003ex\u003c/sub\u003e possesses the strongest redox capability, consistent with its highest low-temperature activity but narrow active temperature window (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;2A\u003c/strong\u003e). Zeolite coupling therefore mitigates NH\u003csub\u003e3\u003c/sub\u003e over-oxidation, and synergizes with enhanced acidity to improve high-temperature performance. After K poisoning (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S49\u003c/strong\u003e), pure MnFeO\u003csub\u003ex\u003c/sub\u003e shows the most pronounced loss of reducibility, correlating with its severe deactivation (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;2D\u003c/strong\u003e).\u0026nbsp;XPS\u0026nbsp;analysis (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e3C\u003c/strong\u003e and \u003cstrong\u003eTable S7\u003c/strong\u003e) reveals that pure MnFeO\u003csub\u003ex\u003c/sub\u003e has the highest Mn\u003csup\u003e4+\u003c/sup\u003e fraction (39.6%)\u003csup\u003e31\u003c/sup\u003e,\u0026nbsp;which facilitates NO oxidation to NO\u003csub\u003e2\u003c/sub\u003e and promotes low-temperature fast SCR\u003csup\u003e32\u003c/sup\u003e.\u0026nbsp;Zeolite coupling decreases the Mn\u003csup\u003e4+\u003c/sup\u003e proportion, with MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 showing the lowest (29.4%), consistent with its moderated redox behavior.\u0026nbsp;After SO\u003csub\u003e2\u003c/sub\u003e exposure (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;2B\u003c/strong\u003e), the Mn\u003csup\u003e4+\u003c/sup\u003e content of pure MnFeO\u003csub\u003ex\u003c/sub\u003e (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S\u003c/strong\u003e\u003cstrong\u003e50\u003c/strong\u003e) decreases sharply, whereas MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;3C\u003c/strong\u003e\u003cstrong\u003e)\u003c/strong\u003e shows only a slight reduction (29.4%\u0026rarr;28.3%). This decrease arises from electron transfer from SO\u003csub\u003e2\u003c/sub\u003e to Mn\u003csup\u003e4+\u003c/sup\u003e\u003csup\u003e33,34\u003c/sup\u003e, leading to sulfate formation and site deactivation. Notably,\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5\u0026nbsp;exhibits the lowest surface sulfur content (\u003cstrong\u003eTable S7\u003c/strong\u003e), further corroborated by SO\u003csub\u003e2\u003c/sub\u003e-TPD (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S51\u003c/strong\u003e). After K poisoning (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;S5\u003c/strong\u003e\u003cstrong\u003e2\u003c/strong\u003e), the Mn\u003csup\u003e4+\u003c/sup\u003e fraction in pure MnFeO\u003csub\u003ex\u003c/sub\u003e decreases markedly, while coupled catalysts remain largely unaffected, explaining their preserved low-temperature activity (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003es.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003cstrong\u003eC\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eand\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS43\u003c/strong\u003e).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMn \u003cem\u003eK\u003c/em\u003e-edge X-ray absorption near-edge structure (XANES) spectra (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e3D\u003c/strong\u003e) confirm that pure MnFeO\u003csub\u003ex\u003c/sub\u003e has the highest Mn oxidation state. Zeolite coupling shifts the absorption edge to lower energies, with MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5 exhibiting\u0026nbsp;a higher Mn valence state than MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5, consistent with XPS\u0026nbsp;results. After SO\u003csub\u003e2\u003c/sub\u003e poisoning (\u003cstrong\u003eFig. 2B\u003c/strong\u003e), both MnFeO\u003csub\u003ex\u003c/sub\u003e/ZSM-5 and MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 exhibit decreased Mn valence (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;3E\u003c/strong\u003e), but the shift is substantially smaller for the yolk-shell catalyst, highlighting the protective role of the zeolite shell. Fourier-transformed (FT) \u003cem\u003ek\u0026sup3;\u003c/em\u003e-weighted extended X-ray absorption fine structure (EXAFS; \u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;3F\u003c/strong\u003e) shows shorter Mn-O bond distances in the composite catalysts than in pure MnFeO\u003csub\u003ex\u003c/sub\u003e, indicative of stronger oxide-zeolite interactions. Wavelet transform analysis (\u003cstrong\u003eFig\u003c/strong\u003e\u003cstrong\u003es.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;3G\u003c/strong\u003e-\u003cstrong\u003eI\u003c/strong\u003e) identifies Mn-O and Mn-Mn/Mn-Fe coordination features\u003csup\u003e35\u003c/sup\u003e, confirming the structural integrity of the encapsulated MnFeO\u003csub\u003ex\u003c/sub\u003e phase.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eReaction pathway and dual-shielding mechanism.\u0026nbsp;\u003c/strong\u003eTo elucidate the NH\u003csub\u003e3\u003c/sub\u003e-SCR reaction pathways, \u003cem\u003ein situ\u0026nbsp;\u003c/em\u003ediffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) was conducted at 200 \u0026deg;C. For MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5, NH\u003csub\u003e3\u003c/sub\u003e adsorption (\u003cstrong\u003eFigs. 4A\u003c/strong\u003e and \u003cstrong\u003e4A\u003csub\u003e1\u003c/sub\u003e\u003c/strong\u003e) revealed significantly stronger bands for both L acid-bound NH\u003csub\u003e3\u003c/sub\u003e (NH\u003csub\u003e3\u003c/sub\u003e-L)\u003csup\u003e36\u003c/sup\u003e and B acid-bound NH\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e species (NH\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e-B)\u003csup\u003e37,38\u003c/sup\u003e compared to pure MnFeO\u003csub\u003ex\u003c/sub\u003e (\u003cstrong\u003eFig. S53\u003c/strong\u003e), confirming that zeolite encapsulation introduces abundant L and B acid sites, thereby enhancing NH\u003csub\u003e3\u003c/sub\u003e adsorption, consistent with the NH\u003csub\u003e3\u003c/sub\u003e-TPD results. Upon introducing NO + O\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eto pre-adsorbed NH\u003csub\u003e3\u003c/sub\u003e, the NH\u003csub\u003e3\u003c/sub\u003e-L/NH\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e-B bands on MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 decreased gradually without the formation of surface nitrate or nitrite intermediates over 40 min (\u003cstrong\u003eFigs. 4B\u003c/strong\u003e and \u003cstrong\u003e4B\u003csub\u003e1\u003c/sub\u003e\u003c/strong\u003e). In contrast, pure\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e (\u003cstrong\u003eFig. S54\u003c/strong\u003e) showed rapid consumption of NH\u003csub\u003e3\u003c/sub\u003e-L species\u003csup\u003e39\u003c/sup\u003e and immediate accumulation of monodentate nitrate\u003csup\u003e40\u003c/sup\u003e and bridged nitrate\u003csup\u003e41\u003c/sup\u003e. Consistently, NO + O\u003csub\u003e2\u003c/sub\u003e adsorption experiments on MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 (\u003cstrong\u003eFig. 4C\u003c/strong\u003e) produced virtually no surface nitrogen species over 40 min, except for a weak transient NO\u003csub\u003e2\u003c/sub\u003e band\u003csup\u003e42\u003c/sup\u003e that disappears upon N\u003csub\u003e2\u003c/sub\u003e purging, unlike pure MnFeO\u003csub\u003ex\u003c/sub\u003e, which formed substantial nitrates/nitrites (\u003cstrong\u003eFig. S55\u003c/strong\u003e). These results demonstrate that the NH\u003csub\u003e3\u003c/sub\u003e-SCR reaction over MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 predominantly follows the E-R mechanism, involving gaseous NO reacting directly with adsorbed NH\u003csub\u003e3\u0026nbsp;\u003c/sub\u003especies. Conversely, pure\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e primarily proceeds via a L-H pathway involving surface nitrate intermediates (\u003cstrong\u003eFig. S56\u003c/strong\u003e), and this mechanistic divergence is further supported by NO-TPD observations (\u003cstrong\u003eFig. S57\u003c/strong\u003e). The substantially stronger oxidative capability of pure\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e, as evidenced by H\u003csub\u003e2\u003c/sub\u003e-TPR, XPS, and XAFS analyses, facilitates NO oxidation to NO\u003csub\u003e2\u003c/sub\u003e and enables the \u0026ldquo;fast SCR\u0026rdquo; pathway at low temperatures, yet simultaneously promotes nitrate accumulation, NH\u003csub\u003e4\u003c/sub\u003eNO\u003csub\u003e3\u003c/sub\u003e decomposition, and the formation of undesired N\u003csub\u003e2\u003c/sub\u003eO. In contrast, zeolite encapsulation attenuates NO adsorption and oxidation, suppresses nitrate/nitrite formation, and thereby enhances N\u003csub\u003e2\u003c/sub\u003e selectivity across a broad temperature range. Density functional theory (DFT) calculations further support these findings. As shown in\u003cstrong\u003e\u0026nbsp;Figs. 4D\u003c/strong\u003e-\u003cstrong\u003eG\u0026nbsp;\u003c/strong\u003eand\u003cstrong\u003e\u0026nbsp;S58\u003c/strong\u003e-\u003cstrong\u003eS59\u003c/strong\u003e, NO adsorption on Mn and Fe sites of pure\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e is strong, with adsorption energies (\u003cem\u003eE\u003csub\u003eads\u003c/sub\u003e\u003c/em\u003e) of \u0026minus;2.607 eV (Mn, \u003cstrong\u003eFig. 4D\u003c/strong\u003e) and \u0026minus;4.100 eV (Fe, \u003cstrong\u003eFig. 4E\u003c/strong\u003e), respectively. In contrast, NO adsorption on\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 is significantly weakened, with corresponding \u003cem\u003eE\u003csub\u003eads\u003c/sub\u003e\u003c/em\u003e of \u0026minus;1.686 eV (Mn, \u003cstrong\u003eFig. 4F\u003c/strong\u003e) and \u0026minus;2.971 eV (Fe, \u003cstrong\u003eFig. 4G\u003c/strong\u003e), consistent with the experimentally observed suppression of surface nitrate formation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe adsorption behavior of SO\u003csub\u003e2\u003c/sub\u003e was further examined by DFT calculations (\u003cstrong\u003eFigs. 5A\u003c/strong\u003e-\u003cstrong\u003eD\u003c/strong\u003e). Relative to pure MnFeO\u003csub\u003ex\u003c/sub\u003e, SO\u003csub\u003e2\u003c/sub\u003e adsorption on MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 is substantially weakened, accompanied by elongated S-Mn and S-Fe bond lengths. Remarkably, SO\u003csub\u003e2\u003c/sub\u003e adsorption on Fe sites becomes thermodynamically unfavorable (\u003cem\u003eE\u003csub\u003eads\u003c/sub\u003e\u003c/em\u003e = +0.383 eV), indicating that the zeolite shell effectively suppresses SO\u003csub\u003e2\u003c/sub\u003e binding. Moreover, SO\u003csub\u003e2\u003c/sub\u003e adsorption on B acid sites of ZSM-5 is also unfavorable (\u003cem\u003eE\u003csub\u003eads\u003c/sub\u003e\u003c/em\u003e =\u0026thinsp;+0.496\u0026thinsp;eV; \u003cstrong\u003eFig. S60\u003c/strong\u003e), reflecting electrostatic repulsion that further inhibits sulfur uptake. To directly probe the structural stability of active sites under SO\u003csub\u003e2\u003c/sub\u003e exposure, \u003cem\u003ein situ\u003c/em\u003e EXAFS measurements were performed during transient SO\u003csub\u003e2\u003c/sub\u003e + O\u003csub\u003e2\u003c/sub\u003e treatment at 246 \u0026deg;C (consistent with the temperature used in the SO\u003csub\u003e2\u003c/sub\u003e resistance test shown in Fig. 2B). As shown in \u003cstrong\u003eFig. 5E\u003c/strong\u003e, the Mn \u003cem\u003eK\u003c/em\u003e-edge XANES profiles of\u0026nbsp;MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 remain essentially unchanged after 2-3 h of SO\u003csub\u003e2\u003c/sub\u003e + O\u003csub\u003e2\u003c/sub\u003e exposure. Correspondingly, the Mn-O peak position in Fourier-transform EXAFS spectra (\u003cstrong\u003eFig. S61\u003c/strong\u003e) and the Mn-O coordination number (~4.9), as well as the bond distance (~1.91 \u0026Aring;) (\u003cstrong\u003eFigs. 5F\u003c/strong\u003e-\u003cstrong\u003eH\u003c/strong\u003e) show negligible variation, confirming that SO\u003csub\u003e2\u003c/sub\u003e does not significantly interact with or perturb the encapsulated MnFeO\u003csub\u003ex\u003c/sub\u003e active sites.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCollectively, these results establish a dual-shielding mechanism for SO\u003csub\u003e2\u003c/sub\u003e resistance in the yolk-shell MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 nanoreactor (\u003cstrong\u003eFig. 5I\u003c/strong\u003e). The crystalline ZSM-5 shell physically isolates the MnFeO\u003csub\u003ex\u003c/sub\u003e core from direct sulfur attack, while its B acid sites electrostatically repel SO\u003csub\u003e2\u003c/sub\u003e and suppress its adsorption. This synergistic physical and chemical shielding not only preserves the structural integrity of the active phase but also enforces an E-R reaction pathway, thereby underpinning the remarkable activity, selectivity, and durability of the nanoreactor under harsh, multi-poisoning SCR conditions.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn summary, we successfully realize the nanoreactor concept for NO\u003csub\u003ex\u003c/sub\u003e reduction by constructing a yolk-shell MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalyst that addresses the long-standing challenge of simultaneous SO\u003csub\u003e2\u003c/sub\u003e and alkali poisoning in NH\u003csub\u003e3\u003c/sub\u003e-SCR. While the synergistic coupling of zeolites and metal oxides has been extensively explored to mitigate deactivation, previous approaches, largely limited to simple mixing or impregnation, failed to achieve both high redox-site content and effective protection. We overcome this limitation through an impregnation-dissolution-recrystallization strategy that enables the confinement of high-content (\u0026gt;10 wt.%) MnFeO\u003csub\u003ex\u003c/sub\u003e nanoparticles within a hollow ZSM-5 single-crystal shell, yielding a robust yolk-shell nanoreactor with preserved zeolite framework integrity. This architecture reveals a synergistic dual-shielding mechanism governing its superior poisoning resistance: the ZSM-5 shell physically hinders the MnFeO\u003csub\u003ex\u003c/sub\u003e core from being directly exposed to SO\u003csub\u003e2\u003c/sub\u003e, whereas its abundant external Br\u0026oslash;nsted acid sites provide chemical shielding by preferentially adsorbing alkali metal and suppressing SO\u003csub\u003e2\u003c/sub\u003e adsorption. This synergistic protection delivers \u0026gt;90% NO\u003csub\u003ex\u003c/sub\u003e conversion with high N\u003csub\u003e2\u003c/sub\u003e selectivity under simultaneous SO\u003csub\u003e2\u003c/sub\u003e and K poisoning. The strategy further demonstrates broad versatility, extending successfully to other mixed metal oxides such as MnCoO\u003csub\u003ex\u0026nbsp;\u003c/sub\u003eand MnCeO\u003csub\u003ex\u003c/sub\u003e. By establishing this yolk-shell architecture as a general platform, our work introduces a powerful paradigm for engineering durable SCR catalysts. More broadly, the hollow zeolite-confined nanoreactor concept opens new avenues for robust catalysts in emission control and other high-temperature environmental processes requiring long-term stability against complex poisons.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eCatalyst synthesis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe yolk-shell MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 catalyst was synthesized by an impregnation-dissolution-recrystallization (IDR) strategy.\u0026nbsp;For comparison, MnFeO\u003csub\u003ex\u003c/sub\u003e metal oxides supported on the outer surface of ZSM-5 was prepared by the conventional impregnation method.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eTo\u0026nbsp;reveal the formation mechanism of MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5, the samples crystallized at each step were collected. Furthermore, to verify the universality of the IDR method, ZSM-5 zeolite confining other metal active sites were also prepared. The detailed preparation procedures are discussed in the Supplementary Information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCharacterization methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eVarious testing methods\u0026mdash;including X-ray diffraction (XRD), N\u003csub\u003e2\u003c/sub\u003e adsorption/desorption analysis, X-ray photoelectron spectroscopy (XPS), pyridine infrared (Py-IR), NH\u003csub\u003e3\u003c/sub\u003e temperature-programmed desorption (NH\u003csub\u003e3\u003c/sub\u003e-TPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM (HRTEM), energy-dispersive X-ray spectroscopy (EDS) elemental mapping, aberration-corrected TEM (AC-TEM), AC-EDS elemental mapping, X-ray absorption near-edge structure (XANES), \u003cem\u003ein situ\u003c/em\u003e extended X-ray absorption fine structure (\u003cem\u003ein situ\u003c/em\u003e EXAFS), density functional theory (DFT) calculations, and the \u003cem\u003ein situ\u003c/em\u003e diffuse reflectance infrared Fourier-transform spectroscopy (\u003cem\u003ein situ\u003c/em\u003e DRIFTS)\u0026mdash;were adopted to measure the physical and chemical properties and elucidate the plausible reaction mechanism over the yolk-shell MnFeO\u003csub\u003ex\u003c/sub\u003e@YS-ZSM-5 and related samples. The detailed measuring processes are described in the Supplementary Information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eActivity and kinetic tests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe detailed NH\u003csub\u003e3\u003c/sub\u003e-SCR activity and kinetic tests are also presented in the Supplementary Information.\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe additional data are provided in the Supplementary Information. All the data that support the findings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the National Natural Science Foundation of China (22476078, 22376222, 22276086 and 22306086), National key R\u0026amp;D Program of China (2023YFA1508400 and 2024YFC3712104), the Natural Science Foundation of Jiangxi Province (20243BCE51169, 20232BCJ22003, 20232BAB213028 and 20242BAB25144), Science and Technology Innovation Program of Hunan Province (2023RC1012), Central South University Research Program of Advanced Interdisciplinary Studies (Grant 2023QYJC012) and the Natural Science Foundation of Chongqing (CSTB2023NSCQ-MSX0950, CSTB2024NSCQ-MSX1295), all of which are greatly acknowledged by the authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eH. Peng conceived the research idea, designed the experiments, and supervised this project, wrote-review \u0026amp; edited the manuscript. Y. Li performed the experiments, analyzed the data, and wrote the manuscript. G. Li performed the DFT calculations. R. Li took part in the synthesis of samples and characterizations. M. Liu commented on the manuscript and wrote-review \u0026amp; edited the manuscript. J. Ji, X. Hu, F. Yu, H. Li, and W. Liu discussed the results and commented on the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing financial interests.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLi, Z. et al. 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Technol.\u003c/em\u003e \u003cstrong\u003e54\u003c/strong\u003e, 15499-15506 (2020).\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"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":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"NH3-SCR, NOx abatement, Multiple poisons, Yolk-shell, Zeolite","lastPublishedDoi":"10.21203/rs.3.rs-9293985/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9293985/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe practical application of ammonia selective catalytic reduction (NH\u003csub\u003e3\u003c/sub\u003e-SCR) for stationary NO\u003csub\u003ex\u003c/sub\u003e abatement is severely restricted by rapid catalyst deactivation in flue gases containing SO\u003csub\u003e2\u003c/sub\u003e and alkali metal. Although coupling zeolites with transition-metal oxides improves poisoning tolerance, most adopted loading or confining strategies cannot simultaneously ensure high redox-site content and effective protection. Herein, we realize a zeolite-confined nanoreactor concept by constructing a yolk-shell catalyst, in which high-content (\u0026gt;10 wt.%) MnFeO\u003csub\u003ex\u003c/sub\u003e nanoparticles are confined within a hollow ZSM-5 single-crystal shell, with the zeolite framework fully preserved. \u003cem\u003eIn situ\u003c/em\u003e X-ray absorption fine structure (XAFS) and diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS), together with density functional theory (DFT) calculations, reveal a synergistic dual-shielding mechanism: the ZSM-5 shell physically hinders SO\u003csub\u003e2\u003c/sub\u003e from attacking the active oxide core, while external Brønsted acid sites chemically suppress SO\u003csub\u003e2\u003c/sub\u003e adsorption and intercept alkali metal. Consequently, the catalyst maintains \u0026gt;90% NO\u003csub\u003ex \u003c/sub\u003econversion with high N\u003csub\u003e2\u003c/sub\u003e selectivity under co-poisoning by SO\u003csub\u003e2\u003c/sub\u003e and K. This work establishes hollow zeolite-confined nanoreactors as a versatile platform for designing durable emission-control catalysts, enabling stable long-term operation under industrially relevant multi-poisoning conditions.\u003c/p\u003e","manuscriptTitle":"Yolk-Shell Zeolite Nanoreactors Enable Multi‑Poison Resistance for NOx Reduction","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-14 12:47:33","doi":"10.21203/rs.3.rs-9293985/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"nature-communications","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"NCOMMS","sideBox":"Learn more about [Nature Communications](http://www.nature.com/ncomms/)","snPcode":"","submissionUrl":"https://mts-ncomms.nature.com/","title":"Nature Communications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature Communications","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"3758e2ad-acfe-41b9-a421-5e2079aec1ed","owner":[],"postedDate":"April 14th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"revise","date":"2026-05-01T14:26:32+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":66295825,"name":"Earth and environmental sciences/Environmental sciences/Environmental chemistry/Pollution remediation"},{"id":66295826,"name":"Physical sciences/Chemistry/Catalysis/Heterogeneous catalysis"}],"tags":[],"updatedAt":"2026-05-01T14:30:44+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-14 12:47:33","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9293985","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9293985","identity":"rs-9293985","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}