A single reaction-based model describes the stepped polarization curves of oxygen evolution recorded on rotating disk electrodes from mildly alkaline solutions
The paper authored by Á. Hideg,
N. Kovács,
É. Fekete,
M. Ujvári,
Zs. Szakály,
T. Romann, V. Grozovski, L. Gálvez-Vázquez, A. Bornet, P. Moreno-García, P. Broekmann, and
S. Vesztergom
is published in Journal of Catalysis (2026, 116974).
Abstract:
Oxygen evolution reaction (OER) polarization curves recorded on rotating disk electrodes in mildly alkaline media exhibit a stepped shape: two exponentially rising segments (the first commonly assigned to OH⁻, the second to water oxidation) are separated by a limiting current plateau. We present here a robust analytical model using only three model parameters for the full polarization curve by assuming that OER proceeds according to a single two-electron charge transfer reaction, OH⁻ ⇌ ½ O₂ + H⁺ + 2e⁻, obeying the Erdey-Grúz–Volmer–Butler equation. The presented model can well be fitted to experimental data obtained for OER on oxidized iridium, platinum, and gold, over a broad range of pH, rotation rate, and electrode potential. The determined kinetic parameters (reaction rate and charge transfer coefficients) can be used to benchmark the catalytic activity of different electrode materials, while the obtained transport parameter (diffusion coefficient) can effectively support system optimization processes.