Copper Doping Enhances the Activity and Selectivity of Atomically Precise Ag ₄₄ Nanoclusters for Photocatalytic CO ₂ Reduction

Abstract Understanding the structure‐activity correlations of bimetallic catalysts is of great importance in designing highly efficient catalytic systems. Herein, the successful doping of up to six copper atoms into an atomically precise Ag ₄₄ nanocluster (NC) is reported. An occupation preference of the copper atoms in the structure of (AgCu) ₄₄ is observed. Both theoretical and experimental studies revealed that the introduction of Cu atoms positively influences the charge carrier distribution and enhances charge separation within the NCs. As a result, the performance of (AgCu) ₄₄ /TiO ₂ in the photocatalytic CO ₂ reduction reaction is two times higher than that of Ag ₄₄ /TiO ₂ . Moreover, the selectivity toward CH ₄ is enhanced threefold due to the moderate binding energy of Cu for CO.