In the context outlined above, we employed defect-induced [Cu58H20(SPr)36(PPh3)7] 2+ (Pr = CH2CH2CH3) (Cu58-I) and [Cu58H20(SEt)36(PPh3)6] 2+ (Et = CH2CH3) (Cu58-II) NCs as catalysts for the highly selective electrochemical reduction of CO2. The remarkable selectivity of the reduction product and the catalytic activity primarily stem from the distinctive structural architecture of the catalyst. Comparative analysis with a regular [Cu58H20(SPr)36(PPh3)8] 2+ (Cu58) NC highlights the superiority of the surface ligand vacancy and the consequent rearrangement of Cu(I) atoms. These structural features greatly enhance the efficacy of the electrochemical reduction approach for CO2. However, the specificities have some limitations, which are finely adjusted by the structural architecture of the NC catalyst. Theoretical studies have identified the active catalytic sites, which are closely associated with the vacant ligand sites. The rearrangement in these sites predominantly dictate the selectivity of the product, emphasizing the crucial role played by the architecture of the NC in governing the catalytic process.