Seed-assisted Formation of Robust Anode Catalysts for Anion Exchange Membrane Water Electrolysis with Industrial-Scaled Current Density

Abstract Alkaline oxygen evolution reaction (OER) is critical for green hydrogen production from water electrolysis but encounters great challenges when operated at industrial-required ampere-scaled current densities, such as insufficient mass transfer, reduced catalytic activity, and limited lifetimes. Here we developed a one-step seed-assisted heterogeneous nucleation (HN) method (25 °C, 24 h) for producing a nickel iron-based electrocatalyst (CAPist-L1) for robust OER at ≥ 1000 mA cm -2 . Based on the insoluble nanoparticles in the HN system (generated from the solubility difference of salts in water and organic solvents), a dense interlayer was formed and anchored the catalyst layer tightly on the substrate, ensuring stable long-term durability of over 14000 h (> 20 months) in 1 M KOH at 1000 mA cm -2 . When applying CAPist-L1 as the anode catalyst in practical anion exchange membrane water electrolysis (AEM-WE), it delivered high activity of 7350 mA cm -2 at 2.0 V and good stability at 1000 mA cm -2 for 1500 h at 80 °C. The low cost and simplicity characteristics make the HN strategy a valuable approach for developing stable OER catalysts for the industrialization of AEM-WE.