Supported Ir-Based Oxygen Evolution Catalysts for Polymer Electrolyte Membrane Water Electrolysis: A Minireview

Renewable energy sources are considered to play a key role in the future energy mix, with hydrogen being an important energy carrier as a long-term energy storage option. Polymer electrolyte membrane (PEM) water electrolysis (WE) allows the relatively quick and convenient production of pure hydrogen from only water and electricity; thus it is considered as one of the most practical ways to consume renewable energy for green hydrogen production. The efficiency of water splitting largely depends on the intrinsic activity, selectivity, and stability of the oxygen evolution electrocatalysts, currently based on noble metals (e.g., Ir or Ru), for PEM technology. The utilization of various support materials has been proposed for decreasing the noble metal loading, reducing costs of the technology, and enhancing the catalytic activity and durability. This minireview addresses recent advances and research prospects in the area of Ir-based supported oxygen evolution catalysts. Besides addressing the intrinsic activity and durability of the supported catalysts, consideration is given to their applications in PEM WE cells. It concludes with mention of challenges and future perspectives.