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 FE_CO 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.