Atomically Dispersed Mo–S Sites Boost NiFe–Layered Double Hydroxide for Industrial‐Level Seawater Electrolysis

ABSTRACT Seawater electrolysis has emerged as a promising pathway for sustainable hydrogen production. However, practical seawater electrolysis is hindered by Cl ⁻ ‐induced site blocking, corrosion, and competitive chlorine evolution. Thus electrocatalysts must achieve high OER currents below the chlorine evolution onset while maintaining structural and chemical stability in Cl ⁻ ‐rich environments. Although noble‐metal‐free NiFe–layered double hydroxide (LDH) is a promising catalyst for oxygen evolution reaction (OER), its practical application in seawater electrolysis remains limited due to its relatively higher overpotentials and Cl ⁻ ‐vulnerability. To overcome this challenge, we report a (Mo–S) ₁ @NiFe–LDH, which incorporates atomically dispersed Mo–S sites within the NiFe–LDH lattice. Spectroscopic analyses confirm that the unique Mo–S coordination induces structural relaxation, lowering the energetic barrier for the transition to active (oxy)hydroxide (NiFeOOH) phase. This facilitated reconstruction enhances reaction kinetics at reduced potential. In a practical seawater anion exchange membrane water electrolyzer (AEMWE), (Mo–S) ₁ @NiFe–LDH exhibits an industrial‐level current density of 5.29 A cm ⁻² at 1.8 V. Furthermore, the system demonstrates stable operation for 425 h under alkalized seawater conditions. This work establishes a design principle for seawater‐resilient catalysts by integrating atomic‐scale coordination with high‐current‐density stability for large‐scale energy conversion.