Promoting Neutral Hydrogen Evolution on Ru Amorphous Sub‐Nanoclusters via Support‐Mediated Interfacial Water Reconstruction in pH‐Asymmetric Electrolyzers

ABSTRACT Neutral hydrogen evolution reaction (HER) is a promising route for sustainable hydrogen (H 2 ) production, yet the sluggish kinetics caused by the rigid hydrogen‐bond (H‐bond) network at the water‐electrode interface remains a critical challenge. Using ab initio molecular dynamics and in‐situ Raman spectroscopy, it is revealed that anchoring Ru amorphous sub‐nanoclusters (Ru‐ASN) on amorphous (CoNiW)O x supports enables electronic metal‐support interaction, triggering electron transfer from Ru to the support. The resulting electron‐rich surface reorients interfacial water into an “H‐down” configuration, disrupting the H‐bond network and increasing weakly H‐bonded water from 6% to 21%. This support‐mediated reconstruction lowers the water dissociation barrier to 0.13 eV, significantly accelerating neutral HER kinetics on Ru sites. The catalyst exhibits a low overpotential of 23 mV at 10 mA cm −2 , with a mass activity 44 times that of Pt/C, and 1000‐h stability. Integrated into a pH‐asymmetric electrolyzer for neutral HER coupled with alkaline sulfur oxidation reaction (SOR), the system delivers 1.0 A cm −2 at only 1.33 V with an energy consumption of 3.18 kWh m −3 H 2 and a Faradaic efficiency exceeding 98%. This pH‑asymmetric coupling strategy thus enables efficient neutral HER and simultaneous sulfur recovery, offering a promising approach for sustainable hydrogen energy and resource utilization.