Mitigating Hidden Failure Mechanisms in IrOx Catalysts for Green Hydrogen Production

Led by Ifan Stephens (Imperial College London)

Team:  CoI: Dr Reshma Rao (Imperial College London)
Research Co-I: Dr. Caiwu Liang (PDRA) (Imperial College London)
Institution/Company: Imperial College London, in collaboration with BP-ICAM, Diamond Light Source, University of Manchester, Helmholtz Zentrum, Forschungszentrum Jülich

“Mitigating Hidden Failure Mechanisms in IrOx Catalysts for Green Hydrogen Production”, led by Ifan Stephens (Imperial College London), tackles one of the most urgent materials challenges facing the Net Zero transition: improving the durability of iridium oxide anodes in proton exchange membrane (PEM) electrolysers. PEM electrolysis is uniquely suited to coupling with intermittent renewable power, yet it relies on scarce and costly IrOx catalysts that degrade under the acidic, high-potential conditions of oxygen evolution. Transient start-up and shutdown events—unavoidable in renewable-powered systems—are known to accelerate degradation, but the mechanistic basis for this remains unclear. This project will employ a range of advanced characterisation techniques to establish the mechanisms of catalyst dissolution under realistic electrolyser operating conditions.

Over 23 months (11 supported by the Hub and 12 co-funded through bp-ICAM), the team will integrate single-cell electrochemical measurements, online ICP-MS, operando optical spectroscopy, X-ray absorption spectroscopy at Diamond Light Source, and advanced microscopy to uncover root causes of shutdown-induced degradation. Crucially, the mechanistic insights will support bp in prolonging electrolyser stack lifetime through improved understanding of iridium degradation mechanisms. The project has attracted substantial industrial backing, underscoring its strategic importance for reducing the levelised cost of green hydrogen. By delivering both fundamental understanding and practical mitigation strategies, this work directly advances the Hub’s Net Zero Transition theme and strengthens the UK’s capability in scalable, durable hydrogen production technologies.