Stabilization by Configurational Entropy of the Cu(II) Active Site during CO Oxidation on Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O

[Image: see text] The mechanisms of CO oxidation on the Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O high-entropy oxide were studied by means of operando soft X-ray absorption spectroscopy. We found that Cu is the active metal and that Cu(II) can be rapidly reduced to Cu(I) by CO when the temperature is hig...

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Autores principales: Fracchia, Martina, Ghigna, Paolo, Pozzi, Tommaso, Anselmi Tamburini, Umberto, Colombo, Valentina, Braglia, Luca, Torelli, Piero
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2020
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8007101/
https://www.ncbi.nlm.nih.gov/pubmed/32309955
http://dx.doi.org/10.1021/acs.jpclett.0c00602
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author Fracchia, Martina
Ghigna, Paolo
Pozzi, Tommaso
Anselmi Tamburini, Umberto
Colombo, Valentina
Braglia, Luca
Torelli, Piero
author_facet Fracchia, Martina
Ghigna, Paolo
Pozzi, Tommaso
Anselmi Tamburini, Umberto
Colombo, Valentina
Braglia, Luca
Torelli, Piero
author_sort Fracchia, Martina
collection PubMed
description [Image: see text] The mechanisms of CO oxidation on the Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O high-entropy oxide were studied by means of operando soft X-ray absorption spectroscopy. We found that Cu is the active metal and that Cu(II) can be rapidly reduced to Cu(I) by CO when the temperature is higher than 130 °C. Co and Ni do not have any role in this respect. The Cu(II) oxidation state can be easily but slowly recovered by treatment of the sample with O(2) at ca. 250 °C. However, it should be noted that CuO is readily and irreversibly reduced to Cu(I) when it is treated with CO at T > 100 °C. Thus, the main conclusion of this work is that the high configurational entropy of Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O stabilizes the rock-salt structure and permits the oxidation/reduction of Cu to be reversible, thus permitting the catalytic cycle to take place.
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spelling pubmed-80071012021-03-30 Stabilization by Configurational Entropy of the Cu(II) Active Site during CO Oxidation on Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O Fracchia, Martina Ghigna, Paolo Pozzi, Tommaso Anselmi Tamburini, Umberto Colombo, Valentina Braglia, Luca Torelli, Piero J Phys Chem Lett [Image: see text] The mechanisms of CO oxidation on the Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O high-entropy oxide were studied by means of operando soft X-ray absorption spectroscopy. We found that Cu is the active metal and that Cu(II) can be rapidly reduced to Cu(I) by CO when the temperature is higher than 130 °C. Co and Ni do not have any role in this respect. The Cu(II) oxidation state can be easily but slowly recovered by treatment of the sample with O(2) at ca. 250 °C. However, it should be noted that CuO is readily and irreversibly reduced to Cu(I) when it is treated with CO at T > 100 °C. Thus, the main conclusion of this work is that the high configurational entropy of Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O stabilizes the rock-salt structure and permits the oxidation/reduction of Cu to be reversible, thus permitting the catalytic cycle to take place. American Chemical Society 2020-04-20 2020-05-07 /pmc/articles/PMC8007101/ /pubmed/32309955 http://dx.doi.org/10.1021/acs.jpclett.0c00602 Text en Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Fracchia, Martina
Ghigna, Paolo
Pozzi, Tommaso
Anselmi Tamburini, Umberto
Colombo, Valentina
Braglia, Luca
Torelli, Piero
Stabilization by Configurational Entropy of the Cu(II) Active Site during CO Oxidation on Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O
title Stabilization by Configurational Entropy of the Cu(II) Active Site during CO Oxidation on Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O
title_full Stabilization by Configurational Entropy of the Cu(II) Active Site during CO Oxidation on Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O
title_fullStr Stabilization by Configurational Entropy of the Cu(II) Active Site during CO Oxidation on Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O
title_full_unstemmed Stabilization by Configurational Entropy of the Cu(II) Active Site during CO Oxidation on Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O
title_short Stabilization by Configurational Entropy of the Cu(II) Active Site during CO Oxidation on Mg(0.2)Co(0.2)Ni(0.2)Cu(0.2)Zn(0.2)O
title_sort stabilization by configurational entropy of the cu(ii) active site during co oxidation on mg(0.2)co(0.2)ni(0.2)cu(0.2)zn(0.2)o
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8007101/
https://www.ncbi.nlm.nih.gov/pubmed/32309955
http://dx.doi.org/10.1021/acs.jpclett.0c00602
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