Sulfur Mediated Interfacial Proton‐Directed Transfer Boosts Electrocatalytic Nitric Oxide Reduction to Ammonia over Dual‐site Catalysts

Electrocatalytic nitric oxide reduction reaction (NORR) for ammonia (NH3) synthesis represents a sustainable strategy that simultaneously realizes the nitrogen cycle and resource integration. The key issue hindering the NORR efficiency is accelerating proton (*H) transfer to facilitate NO hydrogenation while inhibiting hydrogen evolution reaction (HER). Herein, we demonstrate an interface‐engineered sulfur‐mediated Cu@Co electrocatalyst (S‐Cu@Co/C) that boosts NORR performance through dual modulation of electronic structure and proton transfer on active sites. A comprehensive program of experimental and theoretical calculations was employed to discover that sulfur incorporation induces electron redistribution in the Cu‐Co interface, creating electron‐rich sulfur and electron‐deficient metals. This electronic configuration synergistically enhances NO adsorption on Cu sites and promotes water dissociation on Co sites. More critically, sulfur could direct the rapid transfer of *H from Co to Cu sites, thereby accelerating the NO hydrogenation and suppressing HER. Consequently, S‐Cu@Co/C achieves an NH3 yield rate of 655.3 μmol h−1 cm−2 in a flow cell and a Faradaic efficiency of 92.4% in an H‐cell. Remarkably, the catalyst could maintain continuous electrolysis tests and steady NH3 yield up to 100 h. This work provides innovative insights into the fabrication of efficient electrocatalysts via heteroatom‐mediated interfacial engineering strategies.