Constructing Atomic-Level Defect as the Catalytic Site by Removing a Single Metal Atom from the Nanoclusters

In this study, we realized the removal of a single gold atom on the surface of the Au21(AdmS)13S(F3Ph3P) (Au21 for short) cluster by surface engineering and prepared Au20(AdmS)14(PhPy2P) (Au20 for short) with an atomic-level defect. The structural analysis and comparison showed that the 21st gold atom is directly related to the exposure of the ninth gold atom in the core, which can be a catalytically active site. In catalytic comparison, Au20 demonstrates more excellent catalytic activity than Au21 in eCO2RR, with the current density of Au20 being 3 times that of Au21 at −1.3 V. The maximum FECO of Au20 is 92.47%, while that of Au21 is 53.66% at −0.9 V. Finally, theoretical calculations point out that the charge transfer on the ninth gold atom is the most active for the increase in CO2 adsorption and promotes the CO2 reduction reaction.