Kinetics of oxygen reduction reactions involving catalytic decomposition of hydrogen peroxide: Application to porous and rotating ring-disk electrodes

Abstract

Kinetic equations for the combined 2- and 4-electron processes for oxygen reduction in alkaline solution are reexamined for mechanisms involving hydrogen peroxide decomposition of heterogeneous catalytic type. It is shown that previous conclusions regarding these mechanisms apply to porous electrodes only under diffusion-limiting conditions. They have particular significance to diagnostic criteria obtained using the rotating ring-disk electrode technique, and new equations derived here permit unambiguous determination of all the rate constants involved in the reaction by separate kinetic measurements on oxygen and hydrogen peroxide containing solutions.