Er-Modulated NiFe Layered Double Hydroxides for Durable High-Current-Density Seawater Oxidation

Direct seawater electrolysis offers a sustainable route to green hydrogen production, but its practical deployment demands durable anodic catalysts under chloride-rich conditions. Here, we report on the development of Er-incorporated NiFe layered double hydroxide on nickel foam (Er-NiFe LDH/NF) as a robust oxygen-evolution anode for ampere-level seawater oxidation. On one hand, Er functions as a Lewis-acidic center to enrich hydroxide anions and electrostatically repels chloride ions, thereby suppressing chloride-induced corrosion; on the other hand, its unique 4f electronic configuration modulates the electronic structure of NiFe LDH. Consequently, the optimized catalyst achieves a low overpotential of 350 mV at 1000 mA cm-2 and sustains this current density (j) for 1000 h. Moreover, the assembled anion exchange membrane electrolyzer, using Er-NiFe LDH/NF as the anode and Pt/C/NF as the cathode, delivers a j of 500 mA cm-2 at a low cell voltage of 2.20 V with 500 h of stable operation.