Push-pull electronic effects in surface-active sites enhance electrocatalytic oxygen evolution on transition metal oxides
Garcés-Pineda, Felipe A. (Institut Català d'Investigació Química)
Nguyën, Huu Chuong (Institut Català d'Investigació Química)
Blasco-Ahicart, Marta (Institut Català d'Investigació Química)
García-Tecedor, Miguel (Universitat Jaume I. Institute of Advanced Materials)
de Fez Febré, Mabel (Universitat Rovira i Virgili. Departament de Química Física i Inorgànica)
Tang, PengYi (Institut Català de Nanociència i Nanotecnologia)
Arbiol i Cobos, Jordi (Institut Català de Nanociència i Nanotecnologia)
Giménez, Sixto (Universitat Jaume I. Institute of Advanced Materials)
Galán-Mascarós, José Ramón (Institució Catalana de Recerca i Estudis Avançats)
López, Núria (Institut Català d'Investigació Química)

Date:	2021
Abstract:	Sustainable electrocatalysis of the oxygen evolution reaction (OER) constitutes a major challenge for the realization of green fuels. Oxides based on Ni and Fe in alkaline media have been proposed to avoid using critical raw materials. However, their ill-defined structures under OER conditions make the identification of key descriptors difficult. Here, we have studied Fe−Ni−Zn spinel oxides, with a well-defined crystal structure, as a platform to obtain general understanding on the key contributions. The OER reaches maximum performance when: (i) Zn is present in the Spinel structure, (ii) very dense, equimolar 1 : 1 : 1 stoichiometry sites appear on the surface as they allow the formation of oxygen vacancies where Zn favors pushing the electronic density that is pulled by the octahedral Fe and tetrahedral Ni redox pair lowering the overpotential. Our work proves cooperative electronic effects on surface active sites as key to design optimum OER electrocatalysts.
Grants:	European Commission 732840 Ministerio de Economía y Competitividad SEV-2017-0706 Ministerio de Economía y Competitividad ENE2017-85087-C3 Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-327
Note:	Altres ajuts: the authors thankfully acknowledge the computer resources at MareNostrum and the technical support provided by the Barcelona Supercomputing Center (QCM-2018-3-0012 Theoretical studies on catalysis optimization for an Artificial Leaf (A-LEAF)). ICN2 is funded by the CERCA Programme / Generalitat de Catalunya.
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Subject:	Mixed metal oxides ; Spinels ; Oxygen vacancy ; Water splitting ; Descriptors
Published in:	ChemSusChem, Vol. 14, issue 6 (March 2021) , p. 1595-1601, ISSN 1864-564X

DOI: 10.1002/cssc.202002782

Preprint 23 p, 1011.0 KB

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