Jointly Enhanced Nitrate and Water Activation by Precisely Ligand Substituent Regulation in Bimetallic Cluster for Highly Efficient Ammonia Electrosynthesis

ABSTRACT Herein, Cu ₄ Pt ₂ bimetallic series clusters (Cu ₄ Pt ₂ (R‐C ₆ H ₅ ‐C≡C) ₄ (dppy) ₄ (PF ₆ ) ₂ , dppy = diphenyl‐2‐pyridylphosphine, R = CF ₃ , F, MeO, abbreviation as R‐Cu ₄ Pt ₂ ) are synthesized to realize multitask simultaneous processing in NO ₃ RR, in which NO ₃ ⁻ activation and conversion performs on Cu site, while Pt site is responsible for H ₂ O dissociation and *H continuous supplementation. The precisely perturbation in electronic structure of metal active site is further achieved by ligand substituent micro‐regulation strategy. Based on the electron push‐and‐pull effect, as the electron‐withdrawing ability of ligand substituent increases (‐MeO < ‐F < ‐CF ₃ ), the electronic density of metal active site gradually decreases, concurrently promoting NO ₃ ⁻ adsorption and activation, H ₂ O dissociation and *H production, thereby improving NO ₃ RR activity. As a result, CF ₃ ‐Cu ₄ Pt ₂ shows the best NO ₃ RR performance with a high Faradaic efficiency of 91.84% and a satisfactory NH ₃ yield rate of 13.65 mg _NH3 mg _cat ⁻¹ h ⁻¹ at −0.5 V (vs RHE), followed by F‐Cu ₄ Pt ₂ and MeO‐Cu ₄ Pt ₂ . Comprehensive electrochemical experiments, in situ mechanism studies, and theoretical calculations confirm the co‐enhanced NO ₃ ⁻ and H ₂ O activation through fine substituent adjustment. This work not only inspires the construction of multi‐functional catalytic sites with superiority complementation for complex reactions, but also illuminates an achievable pathway to design future advanced catalysts via exquisite ligand micro‐regulation.