3LL-8 : An ultra-low loading iridium on porous gold support for proton exchange membrane water electrolyzer

With interest in global warming, hydrogen produced by water electrolysis is a promising candidate for alternative for fossil fuel. For proton exchange membrane water electrolyzer (PEMWE), Ir-based oxide used as an anode which showed high performance for oxygen evolution reaction (OER). However, its high price and scarcity prevent from commercialization. In this study, low loading Ir-based catalyst on Au were fabricated by self-terminated electrodeposition and subsequent oxidation process. By normalizing the geometric OER activity by electrochemical surface area, intrinsic OER activities were obtained. Through controlling the number of Ir deposition and oxidation process, the Ir valency and electronic structure were modified. Conclusively, it was confirmed that the intrinsic OER activity was strongly affected by electronic structure for Ir-Au interface. Then, fabricated electrode was employed for an anode of PEMWE single-cell and showed remarkable mass activity.