Article
Au and Pt Remain Unoxidized on a CeO2-Based Catalyst during the Water-Gas Shift Reaction
Author/s | Ramírez Reina, Tomás
González Castaño, Míriam López Flores, Víctor Martínez Tejada, Leidy Marcela Zitolo, Andrea Ivanova, Svetlana Xu, Wenquian Centeno Gallego, Miguel Ángel Rodriguez, Jose A. Odriozola Gordón, José Antonio |
Department | Universidad de Sevilla. Departamento de Química Inorgánica |
Publication Date | 2022-01-12 |
Deposit Date | 2024-09-23 |
Published in |
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Abstract | The active forms of Au and Pt in CeO2-based catalysts for the water-gas shift (WGS) reaction are an issue that remains unclear, although it has been widely studied. On one hand, ionic species might be responsible for ... The active forms of Au and Pt in CeO2-based catalysts for the water-gas shift (WGS) reaction are an issue that remains unclear, although it has been widely studied. On one hand, ionic species might be responsible for weakening the Ce-O bonds, thus increasing the oxygen mobility and WGS activity. On the other hand, the close contact of Au or Pt atoms with CeO2 oxygen vacancies at the metal-CeO2 interface might provide the active sites for an efficient reaction. In this work, using in situ X-ray absorption spectroscopy, we demonstrate that both Au and Pt remain unoxidized during the reaction. Remarkable differences involving the dynamics established by both species under WGS atmospheres were recognized. For the prereduced Pt catalyst, the increase of the conversion coincided with a restructuration of the Pt atoms into cuboctahedrical metallic particles without significant variations on the overall particle size. Contrary to the relatively static behavior of Pt0, Au0 nanoparticles exhibited a sequence of particle splitting and agglomeration while maintaining a zero oxidation state despite not being located in a metallic environment during the process. High WGS activity was obtained when Au atoms were surrounded by oxygen. The fact that Au preserves its unoxidized state indicates that the chemical interaction between Au and oxygen must be necessarily electrostatic and that such an electrostatic interaction is fundamental for a top performance in the WGS process |
Funding agencies | Department of Energy. United States Ministerio de Ciencia e Innovación (MICIN). España |
Project ID. | DE-SC001270
RTI2018-096294-B-C33 RYC2018-024387-I |
Citation | Ramírez Reina, T., González Castaño, M., López Flores, V., Martínez Tejada, L.M., Zitolo, A., Ivanova, S.,...,Odriozola Gordón, J.A. (2022). Au and Pt Remain Unoxidized on a CeO2-Based Catalyst during the Water-Gas Shift Reaction. Journal of the American Chemical Society, 144 (1), 446-453. https://doi.org/10.1021/jacs.1c10481. |
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