Research Progress in Iridium-Based Anode Catalysts for PEMWE in Hydrogen Production

As a clean, efficient and renewable energy source, hydrogen energy plays vital roles in China's strategy for the green-oriented transition of energy. Meanwhile, due to the high operational current density, high superior energy efficiency and rapid dynamic response features, proton exchange membrane water electrolysis (PEMWE) technology is gaining increasing attention as a promising method for green and sustainable hydrogen production. Nevertheless, limited by the scarcity and high cost of iridium-based catalysts, which is one of the core components of PEMWE systems, the large-scale application of PEMWE in industrial production is still far from achievable. To meet challenges, great efforts have been made to develop more economical and efficient iridium-based catalysts, to achieve the cost reduction and efficiency improvement issues faced by large-scale application of PEMWE. This review article systematically summarizes the latest advancements of iridium-based anode catalysts for PEMWE. First, the fundamental principles, system configurations and their functions of PEMWE are introduced for better understanding this hydrogen production system. Then, the current application statuses of iridium-based catalysts in the anodic oxygen evolution reaction of PEMWE hydrogen production have been elaborated, including the metal-type, oxide-type and supported-type catalysts. Focus on discussing the influence of morphology control, structural design, and carrier selection on catalytic performance, and propose that future efforts should be dedicated to developing catalysts with low iridium loadings, high activity, and stability.