Perovskite Electrocatalysts for Oxygen Evolution in Alkaline Media: From Fundamentals to Recent Developments

Carrying out electrolytic water splitting in an alkaline environment permits the usage of transition metal-based electrode materials, compared to the significantly more expensive noble metal-based materials required for electrolysis in an acidic environment. Of the two electrode processes that take place in a water electrolyser, the anodic oxygen evolution reaction (OER) is the bottleneck to the process, due to the sluggish kinetics of the reaction; thus, much research is being directed towards developing electrocatalysts to improve the efficiency of this process. Perovskites are a group of compounds that are emerging as promising OER electrocatalysts due to their low cost, good tunability and high catalytic activity. This review begins with the basic principles and fundamental limitations of the OER before exploring the trade-offs between cost, activity, and durability that are often encountered in electrocatalyst design. Perovskites are then introduced as OER electrocatalysts, with a detailed discussion on structure, activity descriptors, catalyst design strategies, and synthesis methods. A critical review of recent advancements in perovskite materials as OER electrocatalysts is then presented at the end, including the latest developments in heteroatom doping and interface engineering.