Dual Modulation of Interfacial Water Structure and Metal‐Support Interaction via Single‐Atom Sites for Industrial Hydrogen Evolution

Ru‐based catalysts are promising cathodes for alkaline hydrogen evolution reaction (HER) in anion exchange membrane water electrolysis (AEMWE), yet sluggish water dissociation, overly strong Ru─H adsorption, and durability loss still limit their practical performance. Herein, we construct a controlled M─N─C (M═Fe, Co, Ni) support series for anchoring Ru particles and establish a dual‐regulation strategy that couples interfacial water activation with support‐induced Ru electronic optimization. M─N 4 coordination motifs mainly regulate the near‐surface water environment and promote water‐dissociation kinetics, while the M─N─C supports modulate the electronic structure of Ru through metal‐support interaction. The optimized Ru/Ni─N─C delivers an ultralow overpotential of 9 mV at 10 mA cm −2 and achieves 4000 mA cm −2 at 2.0 V in a practical AEMWE, with an apparent voltage increase rate of 3.1 µV h −1 over 1600 h. In situ Raman and infrared spectroscopies reveal that Ni─N 4 motifs enrich and polarize interfacial K + ‐H 2 O species, facilitating the Volmer step. Theoretical calculations further show that Ni─N 4 lowers the water dissociation barrier to 0.19 eV, while the Ni─N─C support optimizes Ru─H adsorption to −0.07 eV through metal‐support interaction. This work provides mechanistic guidance for designing efficient Ru‐based alkaline HER catalysts by integrating water‐structure regulation with support‐mediated Ru electronic modulation.