Ultralow-Platinum Cathode Enables High-Performance Anion Exchange Membrane Water Electrolysis

Anion exchange membrane water electrolysis (AEMWE) offers a pathway to reduce noble-metal usage, yet durable platinum (Pt)-free cathodes remain challenging, making ultralow-Pt catalysts still essential. Here, ultrafast Joule-heating creates nonequilibrium Pt-ruthenium (Ru) atomic synergy at 1.6 wt % Pt loading, enabling efficient hydrogen evolution with an overpotential of 28 mV at 10 mA cm −2 . In AEMWE, the catalyst delivers 1 A cm −2 at 1.63 V with a PGM loading of 0.021 mg cm −2 and stable operation for 2600 h. This work provides a cost-efficient strategy for low-Pt cathodes for practical AEMWE.