Dual-interface stabilization of low-iridium anodes for durable proton exchange membrane water electrolysis

The durability and cost of iridium-based anodes remain key challenges for high-current density operation of proton exchange membrane water electrolyzers. Here, we report a dual-interface stabilization strategy based on atomic layer deposition of TiO₂ onto IrO₂ catalysts. The resulting anodes sustain operation at 3.0 A cm^-2 for 2600 h with near-zero voltage degradation at an iridium loading of 0.4 mg cm^-2, whereas bare IrO₂ exhibits continuous voltage decay over 1000 h at a rate of 31.5 mV kh^-1. Combined experimental characterization and theoretical calculations reveal that interfacial Ti-O-Ir coupling suppresses Ir over-oxidation and dissolution, while the TiO₂-coated surface strengthens ionomer-catalyst interactions and preserves mass-transport pathways during prolonged operation. This strategy is fully compatible with roll-to-roll manufacturing, enabling industrially scalable implementation. This interfacial engineering approach offers a generalizable design principle for extending electrolyzer lifetime and reducing precious-metal loading across diverse electrochemical energy conversion technologies.