Tuning Multi-Active Sites in Cu Catalyst via Ag/Ni Doping for Enhanced CO₂ Electroreduction to C₂₊ Products

Electrochemical CO₂ reduction (ECR) to C₂₊ products is a promising sustainable carbon conversion pathway, yet simultaneously achieving high Faradaic efficiency (FE) and current density remains a challenge. Herein, we found that creating Cu-Ag-Ni multi-metal sites could effectively modulate the adsorption energies of *H and *CO on the catalyst surface, thereby achieving highly efficient ECR to synthesize C₂₊ products. In situ measurements coupling theoretical calculations indicated that by systematically altering the spatial arrangement and distribution of active sites in Cu-Ag-Ni catalysts, the electronic structure and the local *CO coverage on the Cu surface could be tuned, consequently steering the ECR to C₂₊ pathway. In particular, Cu-Ag-Ni catalyst with dispersed multi-sites (Cu_xAgNi DNPs) could more effectively reduce the energy barrier for C─C coupling than Cu-Ag-Ni catalyst with phase-separated multi-sites (Cu_xAgNi PNPs). As a result, the Cu₄₀AgNi DNPs catalyst with dispersed multi-sites yielded C₂₊ products with a FE of 93.2% and a current density up to 818.1 mA cm^-2 at -1.38 V versus reversible hydrogen electrode (vs. RHE), which are higher than most reported up to date for C₂₊ production. This work provides a methodology for designing robust multi-metallic ECR catalysts with tailored multi-active site configurations.