Study on amorphous/crystalline iridium oxide as oxygen evolution reaction electrocatalysts for proton exchange membrane water electrolysis

Abstract

Water electrolysis is promising technology for utilizing renewable energy produced intermittently. Iridium oxide is the only electrocatalyst that is both active and stable for the oxygen evolution reaction (OER) in proton exchange membrane water electrolysis (PEMWE). However, iridium oxide is in a trade-off relationship in which stability is decreased when activity is increased. This is a factor that hinders the improvement of electrocatalyst performance. Herein, our group developed AC/NN-20, which improved the performance of NN without stability trade-off by depositing amorphous IrO$_x$ atomic clusters on IrO2 Nanoneedles (NN). The AC/NN-20 showed 1.82 V at 3 A cm$^{-2}$ and was stable for more than 90 hours.