Tuning Asymmetric S‐Bridged Cu─Co Dual Sites at Atomic‐Level for Efficient Ammonia Electrosynthesis

Abstract Electrochemical nitrate reduction reaction (NO ₃ RR) for ammonia production holds immense promise as an environmentally benign strategy. Nevertheless, the process faces inherent limitations by sluggish kinetics of the eight‐electron transfer and multiple competing reactions. Here, an asymmetric S‐bridged Cu, Co dual‐atom (Cu─S─Co) catalyst (CuCo‐SNC) is creatively reported by leveraging the abundant disulfide bond capture and chelation capabilities of wool keratin. Benefiting from the charge regulation effect between the metal sites and S‐bridged atoms, the CuCo‐SNC catalyst exhibits an optimal Faradaic efficiency of 97.8% at −0.3 V (vs RHE) and a remarkable NH ₃ yield rate of 0.88 mmol h ⁻¹ cm ⁻² at −0.6 V (vs RHE). The assembled Zn‐NO ₃ ⁻ battery shows a power density of 7.99 mW cm ⁻² and exceptional cycling stability. Furthermore, in situ characterization and theoretical analysis reveal that the S‐bridge breaks the electron balance between Cu and Co, effectively modulating the charge state of the Cu─Co site, which boosts electrons transfer from Cu to Co site through the S‐bridge, thereby promoting the efficient conversion of nitrate ions (NO ₃ ⁻ ) at Co─Cu bimetallic sites. This asymmetric dual atom catalyst provides a novel perspective for the development of advanced electrocatalytic technologies in ammonia synthesis.