Date of Original Version
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.
Publication Title, e.g., Journal
Li, N., Hadt, R.G., Hayes, D. et al. Detection of high-valent iron species in alloyed oxidic cobaltates for catalysing the oxygen evolution reaction. Nat Commun 12, 4218 (2021). https://doi.org/10.1038/s41467-021-24453-6
Available at: https://doi.org/10.1038/s41467-021-24453-6
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.