Chen, L;
Guan, X;
Wu, X;
Asakura, H;
Hopkinson, DG;
Allen, C;
Callison, J;
... Wang, FR; + view all
(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.
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Thermally stable high-loading single Cu sites on ZSM-5 for selective catalytic oxidation of NHsub3sub.pdf - Accepted Version Download (4MB) | Preview |
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.
| Type: | Article |
|---|---|
| Title: | Thermally stable high-loading single Cu sites on ZSM-5 for selective catalytic oxidation of NH3 |
| Location: | United States |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1073/pnas.2404830121 |
| Publisher version: | https://doi.org/10.1073/pnas.2404830121 |
| Language: | English |
| Additional information: | 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). |
| Keywords: | Ammonia oxidation, heterogeneous catalysis, operando spectroscopy, selective catalytic oxidation, single site catalyst |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10198168 |
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