eprintid: 10198168 rev_number: 7 eprint_status: archive userid: 699 dir: disk0/10/19/81/68 datestamp: 2024-10-08 10:54:25 lastmod: 2024-10-08 10:54:25 status_changed: 2024-10-08 10:54:25 type: article metadata_visibility: show sword_depositor: 699 creators_name: Chen, L creators_name: Guan, X creators_name: Wu, X creators_name: Asakura, H creators_name: Hopkinson, DG creators_name: Allen, C creators_name: Callison, J creators_name: Dyson, PJ creators_name: Wang, FR title: Thermally stable high-loading single Cu sites on ZSM-5 for selective catalytic oxidation of NH3 ispublished: pub divisions: UCL divisions: B04 divisions: F43 keywords: Ammonia oxidation, heterogeneous catalysis, operando spectroscopy, selective catalytic oxidation, single site catalyst note: Copyright © 2024 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND). abstract: Rigorous comparisons between single site- and nanoparticle (NP)-dispersed catalysts featuring the same composition, in terms of activity, selectivity, and reaction mechanism, are limited. This limitation is partly due to the tendency of single metal atoms to sinter into aggregated NPs at high loadings and elevated temperatures, driven by a decrease in metal surface free energy. Here, we have developed a unique two-step method for the synthesis of single Cu sites on ZSM-5 (termed CuS/ZSM-5) with high thermal stability. The atomic-level dispersion of single Cu sites was confirmed through scanning transmission electron microscopy, X-ray absorption fine structure (XAFS), and electron paramagnetic resonance spectroscopy. The CuS/ZSM-5 catalyst was compared to a CuO NP-based catalyst (termed CuN/ZSM-5) in the oxidation of NH3 to N2, with the former exhibiting superior activity and selectivity. Furthermore, operando XAFS and diffuse reflectance infrared Fourier transform spectroscopy studies were conducted to simultaneously assess the fate of the Cu and the surface adsorbates, providing a comprehensive understanding of the mechanism of the two catalysts. The study shows that the facile redox behavior exhibited by single Cu sites correlates with the enhanced activity observed for the CuS/ZSM-5 catalyst. date: 2024-07-23 date_type: published publisher: Proceedings of the National Academy of Sciences official_url: https://doi.org/10.1073/pnas.2404830121 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2299351 doi: 10.1073/pnas.2404830121 medium: Print-Electronic lyricists_name: Wang, Feng lyricists_id: FWANG76 actors_name: Wang, Feng actors_id: FWANG76 actors_role: owner funding_acknowledgements: EP/X022986/1 [UKRI | Engineering and Physical Sciences Research Council (EPSRC)]; EP/S018204/2 [UKRI | Engineering and Physical Sciences Research Council (EPSRC)] full_text_status: public publication: Proceedings of the National Academy of Sciences of the United States of America volume: 121 number: 31 article_number: e2404830121 event_location: United States issn: 0027-8424 citation: Chen, L; Guan, X; Wu, X; Asakura, H; Hopkinson, DG; Allen, C; Callison, J; ... Wang, FR; + view all <#> Chen, L; Guan, X; Wu, X; Asakura, H; Hopkinson, DG; Allen, C; Callison, J; Dyson, PJ; Wang, FR; - view fewer <#> (2024) Thermally stable high-loading single Cu sites on ZSM-5 for selective catalytic oxidation of NH3. Proceedings of the National Academy of Sciences of the United States of America , 121 (31) , Article e2404830121. 10.1073/pnas.2404830121 <https://doi.org/10.1073/pnas.2404830121>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10198168/1/Thermally%20stable%20high-loading%20single%20Cu%20sites%20on%20ZSM-5%20for%20selective%20catalytic%20oxidation%20of%20NHsub3sub.pdf