Self-reconstruction-induced MoO42- generation in Ni–MoN@NF for chloride-resistant seawater-to-H2 conversion

Seawater electrolysis harnesses an abundant resource for sustainable green H 2 production, but is hindered by chloride corrosion and the competing chlorine evolution reaction (CER). We introduce Ni–MoN@NF, a nickel foam-supported transition-metal nitride catalyst that exhibits superior bifunctional OER/HER performance and ultralong stability in alkaline seawater. Under operational potentials, lattice Mo oxidizes and leaches as soluble MoO 4 2- , triggering dual benefits: (i) in situ surface reconstruction to highly active Ni(Mo)OOH oxyhydroxide species with optimized *OH/*OOH intermediates, and (ii) adsorption of residual MoO 4 2- onto the catalyst surface, establishing electrostatic repulsion against Cl⁻ anions to suppress CER, pitting corrosion, and hypochlorite formation. In a full AEM electrolyzer, Ni–MoN@NF delivers industrial-grade current densities of 100 mA cm -2 at record-low cell voltages of 1.70 V (1 M KOH) and 1.75 V (alkaline seawater), maintaining stability over extended operation, representing a pivotal advance for scalable, chloride-resilient H 2 generation.