Ziemba, Marc ; Ganduglia-Pirovano, M. Verónica ; Hess, Christian (2020)
Insight into the mechanism of the water–gas shift reaction over Au/CeO₂ catalysts using combined operando spectroscopies.
In: Faraday Discussions, 229
doi: 10.1039/C9FD00133F
Artikel, Bibliographie
Dies ist die neueste Version dieses Eintrags.
Kurzbeschreibung (Abstract)
The mechanism of the low-temperature water–gas shift (LT-WGS) reaction over Au/CeO₂ catalysts with different ceria terminations, i.e., (111), (110), and (100) facets, was investigated. Using combined operando Raman and UV-Vis spectroscopy as well as isotope exchange experiments, we are able to draw conclusions about the reducibility behaviour and the exchange of surface oxygen. Additional density functional theory (DFT) calculations facilitate the vibrational bands assignments and enhance the interpretation of the results on a molecular level. A facet-dependent role of gold is observed with respect to the oxygen dynamics, since for the CeO₂(111) facet the presence of gold is required to exchange surface oxygen, whereas the CeO₂(110) facet requires no gold, as rationalized by the low defect formation energy of this facet. This behaviour suggests that surface properties (termination, stepped surface) may have a strong effect on the reactivity. While the reduction of the support accompanies the reaction, its extent does not directly correlate with activity, highlighting the importance of other properties, such as the dissociative adsorption of water and/or CO₂/H₂ desorption. The results of our facet-dependent study are consistent with a redox mechanism, as underlined by H₂¹⁸O isotopic exchange experiments demonstrating the ready exchange of surface oxygen.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2020 |
| Autor(en): | Ziemba, Marc ; Ganduglia-Pirovano, M. Verónica ; Hess, Christian |
| Art des Eintrags: | Bibliographie |
| Titel: | Insight into the mechanism of the water–gas shift reaction over Au/CeO₂ catalysts using combined operando spectroscopies |
| Sprache: | Englisch |
| Publikationsjahr: | 22 Januar 2020 |
| Ort: | Cambridge [u.a.] |
| Verlag: | Royal Society of Chemistry |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Faraday Discussions |
| Jahrgang/Volume einer Zeitschrift: | 229 |
| Kollation: | 25 Seiten |
| DOI: | 10.1039/C9FD00133F |
| Zugehörige Links: | |
| Kurzbeschreibung (Abstract): | The mechanism of the low-temperature water–gas shift (LT-WGS) reaction over Au/CeO₂ catalysts with different ceria terminations, i.e., (111), (110), and (100) facets, was investigated. Using combined operando Raman and UV-Vis spectroscopy as well as isotope exchange experiments, we are able to draw conclusions about the reducibility behaviour and the exchange of surface oxygen. Additional density functional theory (DFT) calculations facilitate the vibrational bands assignments and enhance the interpretation of the results on a molecular level. A facet-dependent role of gold is observed with respect to the oxygen dynamics, since for the CeO₂(111) facet the presence of gold is required to exchange surface oxygen, whereas the CeO₂(110) facet requires no gold, as rationalized by the low defect formation energy of this facet. This behaviour suggests that surface properties (termination, stepped surface) may have a strong effect on the reactivity. While the reduction of the support accompanies the reaction, its extent does not directly correlate with activity, highlighting the importance of other properties, such as the dissociative adsorption of water and/or CO₂/H₂ desorption. The results of our facet-dependent study are consistent with a redox mechanism, as underlined by H₂¹⁸O isotopic exchange experiments demonstrating the ready exchange of surface oxygen. |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Physikalische Chemie |
| Hinterlegungsdatum: | 20 Dez 2024 08:46 |
| Letzte Änderung: | 20 Dez 2024 08:49 |
| PPN: | 52494816X |
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| Suche nach Titel in: | TUfind oder in Google |
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Insight into the mechanism of the water–gas shift reaction over Au/CeO₂ catalysts using combined operando spectroscopies. (deposited 05 Dez 2024 13:48)
- Insight into the mechanism of the water–gas shift reaction over Au/CeO₂ catalysts using combined operando spectroscopies. (deposited 20 Dez 2024 08:46) [Gegenwärtig angezeigt]
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