High-Valent Intermediate Observed in a Cu-Based OER Electrocatalyst by Operando X-ray Absorption Spectroscopy

Garcia-Diez R, Wibowo RE, Kataev E, Quevedo Garzon W, van der Merwe M, Duarte-Ruiz D, Cocchi C, Bär M (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Journal of Physical Chemistry Letters American Chemical Society

Pages Range: 6328-6333

DOI: 10.1021/acs.jpclett.5c00944

Abstract

Understanding the chemical transformations governing the oxygen evolution reaction (OER) in Cu-based electrocatalysts is critical for advancing cost-efficient alkaline water-splitting technologies. In this study, we employ synchrotron-based operando Cu L3-edge X-ray absorption spectroscopy (XAS) and potentiodynamic techniques to probe the key intermediate species involved in alkaline OER. Our findings reveal that this metastable species exhibits an electronic structure resembling high-valent Cu complexes, particularly those associated with the CuO2- ion. Potentiodynamic measurements indicate that the high-valent intermediate emerges at potentials as low as 1.62 VRHE, coinciding with the oxidative process traditionally attributed to the Cu2+ ↔ Cu3+ redox transition, suggesting that the formation of the high-valent intermediate is directly linked to this redox process. This work provides valuable insights into the interplay between redox chemistry and catalytic performance in Cu-based OER electrocatalysts and provides further insights into the nature of the chemical species governing the oxygen evolution reaction mechanism.

Authors with CRIS profile

Marcus Bär

Involved external institutions

Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) DE Germany (DE) Carl von Ossietzky Universität Oldenburg DE Germany (DE)

How to cite

APA:

Garcia-Diez, R., Wibowo, R.E., Kataev, E., Quevedo Garzon, W., van der Merwe, M., Duarte-Ruiz, D.,... Bär, M. (2025). High-Valent Intermediate Observed in a Cu-Based OER Electrocatalyst by Operando X-ray Absorption Spectroscopy. Journal of Physical Chemistry Letters, 6328-6333. https://doi.org/10.1021/acs.jpclett.5c00944

MLA:

Garcia-Diez, Raul, et al. "High-Valent Intermediate Observed in a Cu-Based OER Electrocatalyst by Operando X-ray Absorption Spectroscopy." Journal of Physical Chemistry Letters (2025): 6328-6333.

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