Atomically precise M15 (M = Au/Ag/Cu) alloy nanoclusters: Structural analysis, optical and electrocatalytic CO2 reduction properties

Herein, the overall structure of a nanocluster coprotected by phosphine and mercaptan ligands [Au7Ag8(SPh)6((p-OMePh)3P)8]NO3 (Au7Ag8) was reported. For comparison, a previously reported nanocluster with the same structure, but a different metal composition, [Au13Cu2(TBBT)6((p-ClPh)3P)8]SbF6 (Au13Cu2), was synthesized. In addition, their optical and electrocatalytic CO2 reduction properties were comprehensively compared. The results reveal that the photoluminescence quantum yield (PLQY) of the Ag-doped Au7Ag8 nanocluster is 1.62%, which is seven times greater than that of the Cu-doped Au13Cu2 nanocluster (PLQY = 0.23%). Furthermore, the Au13Cu2 nanocluster demonstrates significantly enhanced catalytic selectivity for CO, with a CO Faradaic efficiency ranging from 79.7% to 90.4%, compared with that of the Au7Ag8 nanocluster (CO Faradaic efficiency: 67.2%–77.7%) within a potential range of 0.5 to −1.1 V. From structural analyses, the superior CO selectivity of Au13Cu2 is attributed to the copper dopant