Abstract
Understanding the distinct roles of Brønsted and Lewis acid sites remains a great challenge in designing zeolite catalysts, as their coexistence often obscures mechanistic understanding. Here, we combine solid-state NMR spectroscopy with density functional theory to elucidate the site-specific pathways of ethanol dehydration to ethylene over ZSM-5 zeolite. Two key intermediates are identified: chemisorbed ethanol on Lewis acid sites (LAS) and surface ethoxy species on Brønsted acid sites (BAS), both formed via -OH activation followed by β-H elimination to yield ethylene. Comparative analysis reveals a thermodynamic–kinetic trade-off between the two sites. LAS facilitates low-temperature -OH activation but exhibits high barriers for β-H elimination, limiting ethylene formation. In contrast, BAS requires higher activation energy for -OH activation but enables more facile β-H elimination, promoting ethylene production. This intrinsic trade-off, governed by the thermodynamics of -OH activation, provides a mechanistic basis for understanding and tuning alcohol dehydration on zeolite acid sites.
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All data supporting the findings of this study are available within the article and Supplementary Information files. All data are available from the corresponding author upon request. Source data are provided in this paper.
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Acknowledgements
This work was supported by the National Key R&D Program of China (2023YFB4103600), the National Natural Science Foundation of China (22225205, 22422207, 22320102002, 22127801, U25A20551), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB0540000), the Youth Innovation Promotion Association of the Chinese Academy of Sciences (2021329), Hubei International Scientific and Technological Cooperation program (2024EHA043, SH2303), and the Young Top-notch Talent Cultivation Program of Hubei Province.
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M.H., W.J.C., and C.W. conducted the catalysts preparation, characterization, and catalytic testing; Y.Y.C. performed the DFT calculations; M.H. and Q.W. carried out the solid-state NMR experiments; M.H., Y.Y.C., C.W., J.X., and F.D wrote the manuscript; and C.W. and J.X. designed and directed the project. All authors discussed the results and commented on the manuscript.
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Hu, M., Chu, Y., Wang, C. et al. Unveiling the thermodynamic-kinetic trade-off effect on acid sites in zeolite-catalyzed alcohol dehydration. Nat Commun (2026). https://doi.org/10.1038/s41467-026-70418-y
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DOI: https://doi.org/10.1038/s41467-026-70418-y
