Homoleptic Alkynyl‐Protected Ag15 Nanocluster with Atomic Precision: Structural Analysis and Electrocatalytic Performance toward CO2 Reduction

Abstract We report the fabrication of homoleptic alkynyl‐protected Ag 15 (C≡C‐ t Bu) 12 + (abbreviated as Ag 15 ) nanocluster and its electrocatalytic properties toward CO 2 reduction reaction. Crystal structure analysis reveals that Ag 15 possesses a body‐centered‐cubic (BCC) structure with an Ag@Ag 8 @Ag 6 metal core configuration. Interestingly, we found that Ag 15 can adsorb CO 2 in the air and spontaneously self‐assembled into one‐dimensional linear material during the crystal growth process. Furthermore, Ag 15 can convert CO 2 into CO with a faradaic efficiency of ca. 95.0 % at −0.6 V and a maximal turnover frequency of 6.37 s −1 at −1.1 V along with excellent long‐term stability. Finally, density functional theory (DFT) calculations disclosed that Ag 15 (C≡C‐ t Bu) 11 + with one alkynyl ligand stripping off from the intact cluster can expose the uncoordinated Ag atom as the catalytically active site for CO formation.