Effects of electrolyte cations on the oxygen evolution reaction

Abstract

The oxidation of water to molecular oxygen, referred to as the oxygen evolution reaction (OER), is often the kinetic bottleneck in the formation of renewable fuels. The rate of the OER is strongly dependent on electrolyte properties, such as pH, ionic strength, and the identities of anions and cations. To advance OER catalysis, it is essential to understand the mechanisms by which the electrolyte influences the rate of the OER. In this article, we discuss recent work concerned with the effects of electrolyte cations on the OER. We examine how cations modulate apparent Arrhenius parameters, their effects on the interfacial water structure, their direct interactions with intermediates, and how they alter the rate through non-kinetic effects. The survey reveals that cations can influence the OER through a diversity of mechanisms and that their effects strongly depend on catalyst composition and reaction conditions.