Dual Chloride Confinement in Noble Metal-Doped NiV LDH Catalysts Enables Stable Industrial-Level Seawater...

Seawater electrolysis is an appealing route toward sustainable hydrogen production, yet its practical deployment is hindered by severe chloride-induced corrosion and parasitic chlorine oxidation. Here, we report noble metal-doped NiV layered double hydroxides (LDHs) that integrate electronic modulation with a dual chloride confinement mechanism. Ir incorporation simultaneously establishes strong Ir-Cl coordination and dynamically regenerated VO₄^3- layers, producing an adaptive electrostatic shield that effectively suppresses chloride penetration. As a result, Ir-NiV LDH delivers nearly 100% oxygen evolution reaction selectivity and outstanding stability over 2750 h at 500 mA cm^-2. Meanwhile, Ru doping optimizes the hydrogen evolution pathway, enabling a low overpotential of 195 mV and >2350 h durability. When paired in a twso-electrode electrolyzer, the Ru-NiVLDH||Ir-NiVLDH system exhibits industrial-level performance and unprecedented robustness in alkaline seawater. This dual chloride confinement concept provides a general framework for catalyst design in corrosive ionic environments, extending beyond seawater splitting toward other electrochemical energy conversion processes.