Selective Sulfuration Suppressed Iron Leakage in Nickel–Iron Catalyst to Stimulate Double Lattice Oxygen for Efficient Water Oxidation

Abstract Nickel–iron (NiFe) materials with flexible structure and component have shown all‐right potency for the alkaline oxygen evolution reaction (OER) due to their low reaction barriers. However, most of NiFe catalysts suffer from inferior electrocatalytic stability induced by unfavorable Fe dissolution. Herein, the selective sulfuration of FeOOH/Ni(OH) 2 (NiFe) is developed to construct a reliable Fe─S interaction in FeOOH/Ni 3 S 2 /Ni(OH) 2 (NiFeS) composite and subsequently restrain the Fe dissolution, realizing durable OER stability. X‐ray absorption spectroscopy and theoretical calculations demonstrate that the strong Fe─S interaction affords more electrons to metal sites, thereby stabilizing Fe sites. Meanwhile, the tailored Fe sites with shortened interatomic distance are conducive to inducing double lattice oxygen mechanism (dLOM) for further improving OER activity. Consequently, NiFeS displays a seven‐fold improvement of OER stability and a decreased overpotential compared to NiFe. Moreover, the anion exchange membrane water electrolysis (AEMWE) cell using NiFeS as anode presents an impressive durability for 300 h with negligible attenuation of 0.26 mV h ─1 at 1.0 A cm ─2 at 60 °C. This work provides a new approach to conquer the Fe leakage in NiFe catalysts and enhance the catalytic stability, escorting for their industrial application.