Metal coordination determines the catalytic activity of IrO2 nanoparticles for the oxygen evolution reaction
González, Danilo (Universitat Autònoma de Barcelona. Departament de Química)
Sodupe Roure, Mariona (Universitat Autònoma de Barcelona. Departament de Química)
Rodríguez Santiago, Luis (Universitat Autònoma de Barcelona. Departament de Química)
Solans Monfort, Xavier (Universitat Autònoma de Barcelona. Departament de Química)

Date:	2022
Abstract:	H2 production through water electrolysis is a promising strategy for storing sunlight energy. For the oxygen evolution reaction, iridium oxide containing materials are state-of-the-art due to their stability in acidic conditions. Moreover, precious metal content can be reduced by using small nanoparticles that show high catalytic activities. We performed DFT calculations on a 1. 2 nm large IrO2 Wulff-like stoichiometric nanoparticle model (IrO2) with the aim of determining the factors controlling the catalytic activity of IrO2 nanoparticles. Results show that at reaction conditions tetra- and tricoordinated iridium centers are not fully oxidized, the major species being IrO(OH) and IrO(OH)2, respectively. Although the computed overpotential show that all centers present relatively similar reactivities, low coordinated iridium centers tend to be more active than the pentacoordinates sites of the well-defined facets. These low coordination sites are likely more abundant on amorphous nanoparticles, which could be one of the factors explaining the higher catalytic activity observed for non-crystalline materials.
Grants:	Agencia Estatal de Investigación CTQ2017-89132-P Agencia Estatal de Investigación PID2020-112715GB-I00 Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-1323
Note:	Altres ajuts: acords transformatius de la UAB
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Water electrolysis ; Oxygen Evolution Reaction ; Iridium oxide ; Nanoparticles ; DFT
Published in:	Journal of Catalysis, Vol. 412 (August 2022) , p. 78-86, ISSN 1090-2694

DOI: 10.1016/j.jcat.2022.05.023

9 p, 1.3 MB

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