Polymer electrolyte electrolysis: A review of the activity and stability of non-precious metal hydrogen evolution reaction and oxygen evolution reaction catalysts

The potential for generating green hydrogen by electrolysis (water splitting) has resulted in a substantial amount of literature focusing on lowering the current production cost hydrogen. A significant contributor to this high is requirement precious metals (namely Pt and Ir/Ru (oxides)) catalyse two main reactions involved electrolysis: evolution reaction (HER) oxygen (OER). Herein we overview non-precious metal HER OER catalysts capable efficient water splitting within polymer electrolyte membrane (PEM) electrolyser, recording activity stability each catalyst allowing direct comparison be made. Additionally, highlight inapplicability testing many academic studies commercial electrolyser applications propose universal stability-testing regime that more accurately mimics conditions an operating electrolyser.