Phytic Acid‐Modified Ni ₃ Fe ₁ N With Enhanced Chloride Corrosion Resistance for Efficient and Stable Seawater Oxidation

Developing oxygen evolution reaction (OER) electrodes with high catalytic activity and chloride corrosion resistance is crucial for advancing industrial seawater electrolysis for hydrogen production, yet it remains a significant challenge. In this work, we report a phytic acid (PA)‐modified Ni 3 Fe 1 N electrocatalyst for stable oxidation in both freshwater and seawater. The Ni 3 Fe 1 N–PA catalyst forms a unique multilayered structure, consisting of a conductive Ni 3 Fe 1 N core, an in situ Fe–NiOOH phase, and a phosphate‐rich PA layer. The Ni 3 Fe 1 N–PA electrode exhibits excellent OER performance, high selectivity, and chloride corrosion resistance in chloride‐containing electrolytes. In alkaline seawater, it achieves a current density of 500 mA cm −2 at an overpotential of 320 mV with stability exceeding 2200 h. Integrated into the Ni 3 Fe 1 N–PA || NiMoN cell, it requires only 1.784 V and 1.983 V to output 500 and 1000 mA cm −2 , respectively, maintaining stable operation for over 800 h. Moreover, it requires a cell voltage of only 1.997 V to achieve a current density of 1 A cm −2 in an alkaline anion exchange membrane electrolyzer and can operate stably for over 100 h. This work offers a promising approach for designing corrosion‐resistant anode catalysts for industrial‐scale seawater splitting.