Progress of Ir/Ru-based catalysts for electrocatalytic oxygen evolution reaction in acidic environments

Proton exchange membrane water electrolysis (PEMWE) has been regarded as a promising technology for green hydrogen production due to its efficient combination with intermittent renewable energy sources. Ir/Ru-based catalysts are primarily focused to promote the anodic sluggish oxygen evolution reaction (OER) because of their outstanding intrinsic activity and the high anti-corrosion stability in acidic electrolytes. To achieve a comprehensive insight into the Ir/Ru-based catalysts, this review highlights the recent progress of Ir/Ru-based catalysts to improve their electrochemical performance in terms of low overpotential and high stability, with a focus on the strategies of controlling preferred facet and enhancing atomic utilization. In addition, the applications of in-situ characterization methods are also discussed to understand the real active sites and reveal the reaction mechanisms of Ir/Ru-based catalysts. The objective of this review is to provide new insights into developing efficient Ir/Ru-based catalysts.