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Surface oxidation/spin state determines oxygen evolution reaction activity of cobalt-based catalysts in acidic environment.
- Source :
-
Nature communications [Nat Commun] 2024 Apr 09; Vol. 15 (1), pp. 3067. Date of Electronic Publication: 2024 Apr 09. - Publication Year :
- 2024
-
Abstract
- Co-based catalysts are promising candidates to replace Ir/Ru-based oxides for oxygen evolution reaction (OER) catalysis in an acidic environment. However, both the reaction mechanism and the active species under acidic conditions remain unclear. In this study, by combining surface-sensitive soft X-ray absorption spectroscopy characterization with electrochemical analysis, we discover that the acidic OER activity of Co-based catalysts are determined by their surface oxidation/spin state. Surfaces composed of only high-spin Co <superscript>II</superscript> are found to be not active due to their unfavorable water dissociation to form Co <superscript>III</superscript> -OH species. By contrast, the presence of low-spin Co <superscript>III</superscript> is essential, as it promotes surface reconstruction of Co oxides and, hence, OER catalysis. The correlation between OER activity and Co oxidation/spin state signifies a breakthrough in defining the structure-activity relationship of Co-based catalysts for acidic OER, though, interestingly, such a relationship does not hold in alkaline and neutral environments. These findings not only help to design efficient acidic OER catalysts, but also deepen the understanding of the reaction mechanism.<br /> (© 2024. The Author(s).)
Details
- Language :
- English
- ISSN :
- 2041-1723
- Volume :
- 15
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Nature communications
- Publication Type :
- Academic Journal
- Accession number :
- 38594282
- Full Text :
- https://doi.org/10.1038/s41467-024-47409-y