How to Break the Activity-Stability Conundrum in Oxygen Evolution Electrocatalysis: Mechanistic Insights

Technically viable electrocatalysts for the oxygen evolution reaction (OER) must be both active and stable under the harsh conditions at an electrolyser anode. While numerous highly active metal-oxide catalysts have been identified, only very few are sufficiently stable, with iridium oxides being the most prominent. In this perspective, we draw insights from OER mechanisms to circumvent the activity-stability conundrum generally plaguing the development of OER catalysts. In the commonly considered OER mechanisms, one or several metal-oxygen (M-O) bonds are required to be broken along the OER pathway, providing a mechanistic link between the OER and oxide decomposition. However, a recently discovered mechanism on crystalline iridium dioxide provides a new OER pathway without M-O bond breakages, thus enabling the combination of sufficient activity and stability.