Atomically dispersed Iridium on Indium tin oxide efficiently catalyzes water oxidation
Lebedev, Dmitry (ETH Zürich. Department of Chemistry and Applied Biosciences)
Ezhov, Roman (Purdue University. Department of Physics and Astronomy)
Heras-Domingo, Javier (Universitat Autònoma de Barcelona. Departament de Química)
Comas-Vives, Aleix (Universitat Autònoma de Barcelona. Departament de Química)
Kaeffer, Nicolas (ETH Zürich. Department of Chemistry and Applied Biosciences)
Willinger, Marc (ETH Zurich. Scientific Center for Optical and Electron Microscopy (ScopeM))
Solans Monfort, Xavier (Universitat Autònoma de Barcelona. Departament de Química)
Huang, Xing (ETH Zurich. Scientific Center for Optical and Electron Microscopy (ScopeM))
Pushkar, Yulia (Purdue University. Department of Physics and Astronomy)
Copéret, Christophe (ETH Zürich. Department of Chemistry and Applied Biosciences)

Date:	2020
Abstract:	Heterogeneous catalysts in the form of atomically dispersed metals on a support provide the most efficient utilization of the active component, which is especially important for scarce and expensive late transition metals. These catalysts also enable unique opportunities to understand reaction pathways through detailed spectroscopic and computational studies. Here, we demonstrate that atomically dispersed iridium sites on indium tin oxide prepared via surface organometallic chemistry display exemplary catalytic activity in one of the most challenging electrochemical processes, the oxygen evolution reaction (OER). In situ X-ray absorption studies revealed the formation of Ir V =O intermediate under OER conditions with an Ir-O distance of 1. 83 Å. Modeling of the reaction mechanism indicates that Ir V =O is likely a catalyst resting state, which is subsequently oxidized to Ir VI enabling fast water nucleophilic attack and oxygen evolution. We anticipate that the applied strategy can be instrumental in preparing and studying a broad range of atomically dispersed transition metal catalysts on conductive oxides for (photo)electrochemical applications. Site-isolated Ir on ITO is identified as an efficient acidic water splitting catalyst. In situ spectroscopy and modeling reveal the key Ir V =O intermediate and allow proposing the reaction mechanism.
Grants:	Agencia Estatal de Investigación CTQ2017-89132-P Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-1320 Ministerio de Educación y Ciencia RyC-2016-19930 Agencia Estatal de Investigación PGC2018-100818-A-I00
Note:	This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes: https://pubs.acs.org/page/policy/authorchoice_termsofuse.html
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Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	ACS Central Science, Vol. 6 (July 2020) , p. 1189-1198, ISSN 2374-7951

DOI: 10.1021/acscentsci.0c00604
PMID: 32724853

10 p, 5.5 MB

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