Electronic Structure‐Engineered Proton Depletion Interfaces on Ternary RuO 2 for Ultra‐Stable Kilowatt Electrocatalysis

Advancing high-current PEM water electrolysis (PEMWE) is crucial for terawatt-scale green hydrogen economies, but anode catalyst stability under industrial conditions remains a key barrier to system efficiency and longevity. Here, we present a ternary RuO₂-based catalyst (Cr_0.1Sn_0.1Ru_0.8O₂) that addresses these limitations through proton depletion interface engineering, with electronic structure modulation inherently integrated into the catalyst design. The resulting catalyst reaches a current density of 3.0 amperes per square centimeter at only 1.77 volts and a low degradation for oxygen evolution over 1000 h in PEMWE. A scaled-up system incorporating this anode catalyst further attains a hundred-ampere level water electrolysis, with kilowatt scale which propels the large-scale deployment of hydrogen production utilizing renewable energy sources. Our techno-economic analysis predicts that leveraging this anode architecture can reduce hydrogen production costs below $1 per kg H₂ while maintaining a substantially lower environmental footprint relative to conventional electrolyzer technologies.