Promoting the Corrosion Resistance of Mo‐FeCoP@MnOx/NF via Double Protection Mechanisms Toward Electrolysis of Seawater at Ampere‐Level Current Density

Abstract Producing hydrogen via seawater electrolysis is pivotal for addressing both energy and environmental crises. An industrial‐current‐density electrocatalyst consisting of Mo‐doped FeCoP nanorods decorated with MnO x nanosheets is elaborately designed and grows in situ on nickel foam forming hierarchical Mo‐FeCoP@MnO x /NF (M‐FCP@MnO x /NF) for seawater electrolysis. Density functional theory calculations demonstrate that MnO x species remarkably reduce the adsorption capacity of Cl − , which enhances the corrosion resistance and selectivity of M‐FCP@MnO x /NF during seawater electrolysis. Moreover, incorporating high‐valence Mo species forms a superficial electrostatic layer on electrocatalysts to repel Cl − . Owing to its enhanced double protection mechanism and unique self‐healing characteristics, M‐FCP@MnO x /NF requires overpotentials of only 209 mV (HER) and 270 mV (OER) to reach a current density of ≈1.0 A cm −2 and maintains stable operation over 120 h during alkaline electrolysis of seawater. The colorimetric analysis indicates negligible ClO − production post stability test, indicating that the OER selectivity approaches 100%.