Selective OH − Adsorption and Cl − Repulsion on Cr‐Ni Oxide Supported Single Ir‐Atom for Efficient and Stable Seawater Oxidation
Yuanshuo Ma, Pengfei Wu, Qiu Lv, Zhihao Lou, Da Xue, Pengfei Wang, Fangyi Ma, Xiangyi Weng, Xuejing Cui, Guangbo Liu, Xin Zhou, Luhua JiangABSTRACT
The competitive adsorption of Cl − over OH − presents a major challenge for seawater electrolysis, as it causes severe anode corrosion and low activity, thereby restricting the practical hydrogen production. Herein, chromium‐nickel oxide supported single iridium atom (Ir SA @Cr 2 O 3 /NiO) catalyst was rationally designed, which enables selective OH − adsorption over Cl − for efficient and stable seawater oxidation. Electrochemical evaluations reveal that the resultant Ir SA @Cr 2 O 3 /NiO exhibited outstanding activity for the oxygen evolution reaction (OER), delivering an overpotential of only 215/279 mV at 10/100 mA cm −2 in alkaline seawater electrolytes. The anion‐exchange membrane seawater electrolyzer (AEMSWE) with an Ir SA @Cr 2 O 3 /NiO anode requires a low voltage of only 1.87/2.09 V to reach 500/1000 mA cm −2 . Impressively, the AEMSWE maintains continuous operation at 500 mA cm − 2 for over 1200 h with an ultra‐low degradation rate of 19.83 µV h − 1 , representing two‐orders of magnitude lower than that of an Ir‐NiO anode (4880 µV h − 1 ). Comprehensive in‐situ analysis and density functional theory calculations verified that Cr 2 O 3 effectively modulates the electronic states of the Ir sites, thus enhancing OH − adsorption, suppressing Cl − ‐induced corrosion, and ultimately accelerating both the OER kinetics and selectivity. This work provides new insights for developing highly selective and stable anodes for seawater electrolysis.