Oxygen evolution at oxidized iron electrodes: a tale of two slopes

Abstract

The electro-catalytic activity with respect to water oxidation to form molecular oxygen of iron oxyhydroxide thin films on iron support surfaces in aqueous base is described. A mechanism involving iron surfaquo groups is proposed in excellent agreement with the kinetic data. It is shown that the rate determining step of the oxygen evolution reaction depends strongly on the conditions under which the iron oxyhydroxide film is generated.