A wedge-meniscus model of gas-diffusion electrodes

Abstract

Reactions at gas-diffusion electrodes are modeled by treating the electrolyte meniscus geometry as a wedge. The resulting differential equations are solved analytically for the constant-overpotential case and numerically for all forms of polarization. The model's prediction agrees with experimental data for hydrogen oxidation on platinum in sulfuric acid. The effects of various physical parameters contributing to concentration, ohmic, and activation polarization are considered. The contact angle and the three-phase contact line have not been adequately addressed in previous studies and are shown to be very important parameters. This suggests a new approach in modeling conventional gas-diffusion electrode performance. © 1987.