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DOE OSTI · 2588820

Decoupling the catalytic and degradation mechanisms of cobalt active sites during acidic water oxidation

Simondson, Darcy [Monash Univ., Melbourne, VIC (Australia)]·Tesch, Marc F. [Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr (Germany)] (ORCID:0000000174807200)·Spanos, Ioannis [Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr (Germany)] (ORCID:0000000157374992)·Jones, Travis Elliott Loyd [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000189217641)·Guo, Jining [Monash Univ., Melbourne, VIC (Australia)] (ORCID:0009000217756974)·Kerr, Brittany V. [Swinburne University of Technology, Hawthorn, VIC (Australia)]·Chatti, Manjunath [Monash Univ., Melbourne, VIC (Australia)]·Bonke, Shannon A. [Univ. of Cambridge (United Kingdom)]·Golnak, Ronny [Helmholtz-Zentrum Berlin (HZB), (Germany). German Research Centre for Materials and Energy] (ORCID:0000000254615284)·Johannessen, Bernt [Australian Nuclear Science and Technology Organisation (ANSTO), Clayton, VIC (Australia); Univ. of Wollongong, NSW (Australia)]·Xiao, Jie [Helmholtz-Zentrum Berlin (HZB), (Germany). German Research Centre for Materials and Energy] (ORCID:0000000223206111)·MacFarlane, Douglas R. [Monash Monash Univ., Melbourne, VIC (Australia)] (ORCID:0000000159639659)·Hocking, Rosalie K. [Swinburne University of Technology, Hawthorn, VIC (Australia)] (ORCID:0000000222138786)·Simonov, Alexandr N. [Monash Univ., Melbourne, VIC (Australia)] (ORCID:0000000330636539)
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Abstract

Advancement of iridium-free catalysts for the low-pH oxygen evolution reaction (OER) is required to enable multi-gigawatt-scale proton-exchange water electrolysis. Cobalt-based materials might address this requirement, but little is known about the mechanism of operation of these OER catalysts at low pH. Here we investigate the nature and evolution of the active cobalt sites along with charge- and mass-transfer processes that support their catalytic function within a cobalt–iron–lead oxide material using in situ spectroscopic, gravimetric and electrochemical techniques. We demonstrate that corrosion of the cobalt sites and their reformation through electrooxidation of dissolved Co 2+ do not affect the catalytic mechanism and are decoupled from the OER. The OER-coupled charge transfer is supported by Co (3+δ)+ -oxo-species, which are structurally different from those reported for alkaline/near-neutral conditions and are formed on a relatively slow timescale of minutes. These mechanistic insights might assist in developing genuinely practical catalysts for this vital technology.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYelectrocatalysisenergyhydrogen energy

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Simondson, Darcy [Monash Univ., Melbourne, VIC (Australia)], Tesch, Marc F. [Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr (Germany)] (ORCID:0000000174807200), Spanos, Ioannis [Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr (Germany)] (ORCID:0000000157374992), Jones, Travis Elliott Loyd [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000189217641), Guo, Jining [Monash Univ., Melbourne, VIC (Australia)] (ORCID:0009000217756974), Kerr, Brittany V. [Swinburne University of Technology, Hawthorn, VIC (Australia)], Chatti, Manjunath [Monash Univ., Melbourne, VIC (Australia)], Bonke, Shannon A. [Univ. of Cambridge (United Kingdom)], Golnak, Ronny [Helmholtz-Zentrum Berlin (HZB), (Germany). German Research Centre for Materials and Energy] (ORCID:0000000254615284), Johannessen, Bernt [Australian Nuclear Science and Technology Organisation (ANSTO), Clayton, VIC (Australia); Univ. of Wollongong, NSW (Australia)], Xiao, Jie [Helmholtz-Zentrum Berlin (HZB), (Germany). German Research Centre for Materials and Energy] (ORCID:0000000223206111), MacFarlane, Douglas R. [Monash Monash Univ., Melbourne, VIC (Australia)] (ORCID:0000000159639659), Hocking, Rosalie K. [Swinburne University of Technology, Hawthorn, VIC (Australia)] (ORCID:0000000222138786), Simonov, Alexandr N. [Monash Univ., Melbourne, VIC (Australia)] (ORCID:0000000330636539). 2025-07-16. Decoupling the catalytic and degradation mechanisms of cobalt active sites during acidic water oxidation. https://doi.org/10.1038/s41560-025-01812-x

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