Research Progress on Catalyst Supports for the Oxygen Evolution Reaction in Water Electrolysis

Abstract

The oxygen evolution reaction (OER) is the slow half-reaction of water electrolysis, and its kinetics largely set the ceiling on the energy efficiency of green hydrogen production. In a supported electrode, what the support does is easily overlooked. It controls the dispersion of active components, the efficiency of electron transport, and the lifetime of the electrode; on these three counts rests the practicality of any catalyst. Support design has therefore grown into a central topic of OER research. This review summarizes recent progress on catalyst supports for the OER in water electrolysis, grouping them by the pH window in which they operate: supports common under alkaline OER (carbon materials and metal oxides), supports common under acidic OER (doped tin oxides, titanium-based oxides and suboxides, and conductive carbides and borides), and pH-universal supports (titanium suboxide Ti₄O₇, doped TiO₂, and tungsten carbide). For each family we introduce representative materials, recent preparation strategies, and the performance reached in typical studies, and then compare the advantages and limitations of the different support families in a single table. The review ends with a summary of the field, a point-by-point discussion of current challenges, and the prospects that follow from them, in the hope of providing a workable reference for the rational design of OER catalyst supports.