Shape control of Ir-Ni bimetallic nanoparticles for Ir minimization in oxygen evolution reaction

Abstract

Proton exchange membrane (PEM) water electrolyzer as large scale energy storage system in clean way is needed for utilization of intermittent renewable energy and efficient power generations. However, the efficiency is highly limited by the sluggish kinetics of oxygen evolution reaction (OER). To lower the high overpotential at the OER, Ir is widely used as electrocatalyst. Ir is the only metal which has both high activity and stability at PEM condition. Due to the scarcity and high price of Ir, Ir minimization is important for commercialization of PEM electrolyzers. The shaped Ir-Ni bimetallic nanoparticles were synthesized by facile one step method. Various shapes of Ir-Ni structures were obtained. These bimetallic nanoparticles were used for the OER electrocatalysts showing greatly enhanced Ir mass activity with high stability. I expect this work has implications for the development of PEM based electrolysis.