(Keynote) Kinetic and Non-Kinetic Limitations during Oxygen Evolution Reaction on Nickel-Iron Oxyhydroxide Electrodes

Abstract

The rate and mechanism of the oxygen evolution reaction (OER) depends on many factors. Here, we show on the example of OER on nickel oxy-hydroxide electrodes in alkaline media, how the OER rate depends on pH, cations, nano-catalyst structure, bubble removal, mass transport, temperature and pressure. We illustrate that many of these parameters lead to a higher current (density) but also argue that they often do not actually remove true kinetic barriers. Tafel slope plots or differential Tafel plots are introduced as a powerful tool to separate kinetic from non-kinetic limitations.