Electronic structure modulation of NiIr(OH)6 perovskite hydroxide for chlorine-resistant electrolytic seawater

• • The NiIr(OH)6 catalyst achieves 100 mA cm-2 at an overpotential of only 330 mV in alkaline seawater, outperforming conventional Ni-based catalysts that typically require >400 mV, thus reducing energy consumption by approximately 15% for hydrogen production. • • Long-term durability tests demonstrate stable operation for 190 h under multi-current step testing, with no significant degradation, indicating potential for industrial-scale continuous operation with minimal maintenance downtime. • • DFT calculations show strengthened OH adsorption (-2.09 eV) and suppressed Cl- adsorption (-1.38 eV), which mitigate electrode corrosion and improve OER selectivity to >99%, addressing a critical failure mode in seawater electrolysis. • • The assembled electrolyzer (NiIr(OH)6 || Pt/C) operates at 1.63 V to deliver 100 mA cm-2 and maintains stability for over 100 h, demonstrating a viable pathway for direct seawater splitting with a cell voltage 200 mV lower than typical alkaline water electrolyzers.