Detection of high-valent iron species in alloyed oxidic cobaltates for catalysing the oxygen evolution reaction
Abstract
Iron alloying of oxidic cobaltate catalysts results in catalytic activity for oxygen evolution on par with Ni-Fe oxides in base but at much higher alloying compositions. Zero-field ⁵⁷Fe Mössbauer spectroscopy and X-ray absorption spectroscopy (XAS) are able to clearly identify Fe⁴⁺ in mixed-metal Co-Fe oxides. The highest Fe⁴⁺ population is obtained in the 40–60% Fe alloying range, and XAS identifies the ion residing in an octahedral oxide ligand field. The oxygen evolution reaction (OER) activity, as reflected in Tafel analysis of CoFeOx films in 1 M KOH, tracks the absolute concentration of Fe⁴⁺. The results reported herein suggest an important role for the formation of the Fe⁴⁺ redox state in activating cobaltate OER catalysts at high iron loadings.
Additional Information
© The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Received 27 February 2021; Accepted 15 June 2021; Published 09 July 2021. Material is based upon work supported under the Solar Photochemistry Program of the Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences of the U.S. Department of Energy DE-SC0017619. Data availability: Experimental procedures, characterization of compounds electrochemical and spectral data are available in the Supplementary Information. All data are available from the authors on reasonable request. Author Contributions: N.L., R.G.H., and D.H. conducted the experiments. N.L., R.G.H., D.H., L.X.C., and D.G.N. designed experiments and analysed and interpreted the data. D.G.N. prepared a draft of the manuscript and finalized the manuscript. The authors declare no competing interests. Peer review information: Nature Communications thanks the anonymous reviewers for their contribution to the peer review of this work.Attached Files
Published - s41467-021-24453-6.pdf
Supplemental Material - 41467_2021_24453_MOESM1_ESM.pdf
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Additional details
- Eprint ID
- 109759
- Resolver ID
- CaltechAUTHORS:20210709-180849558
- DE-SC0017619
- Department of Energy (DOE)
- Created
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2021-07-09Created from EPrint's datestamp field
- Updated
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2021-07-09Created from EPrint's last_modified field