High-Performing and Stable Membrane Electrode Assemblies Based on Fluorine-Doped Tin Oxide Catalysts

Abstract To improve the iridium utilization on proton exchange membrane water electrolysers (PEMWEs), a new support based on fluorine-doped tin oxide (FTO) nanoparticles was developed, characterized, and assessed for the anode side. This approach utilizes a sol–gel method combined with a 500 °C annealing treatment to promote favorable metal–support interactions and contribute to catalyst stability. The resulting IrOx/FTO catalyst exhibits remarkable performance at a low Ir loading of 0.5 mgIr cm–2, corresponding to half the loading of the commercial IrO2 reference. The membrane electrode assembly (MEA) incorporating the FTO-based anode outperformed the electrolyzer employing commercial IrO2, reaching 1.35 A cm–2 at 2 V and 60 °C compared with 0.9 A cm–2 for the commercial catalyst. Moreover, these catalysts demonstrated excellent operational stability, with no significant activity decline during more than 300 h of continuous operation at 1.3 A cm–2 and 80 °C. These findings pave the way for innovative and cost-effective membrane electrode assemblies with enhanced stability.