Bipyridine-Assisted Assembly of Au Nanoparticles on Cu Nanowires To Enhance the Electrochemical Reduction of CO₂

We report a new strategy to prepare a composite catalyst for highly efficient electrochemical CO₂ reduction reaction (CO₂ RR). The composite catalyst is made by anchoring Au nanoparticles on Cu nanowires via 4,4'-bipyridine (bipy). The Au-bipy-Cu composite catalyzes the CO₂ RR in 0.1 m KHCO₃ with a total Faradaic efficiency (FE) reaching 90.6 % at -0.9 V to provide C-products, among which CH₃ CHO (25 % FE) dominates the liquid product (HCOO^- , CH₃ CHO, and CH₃ COO^- ) distribution (75 %). The enhanced CO₂ RR catalysis demonstrated by Au-bipy-Cu originates from its synergistic Au (CO₂ to CO) and Cu (CO to C-products) catalysis which is further promoted by bipy. The Au-bipy-Cu composite represents a new catalyst system for effective CO₂ RR conversion to C-products.