Homoleptic Alkynyl-Protected Ag-15 Nanocluster with Atomic Precision: Structural Analysis and Electrocatalytic Performance toward CO2 Reduction

摘要

We report the fabrication of homoleptic alkynyl-protected Ag-15(C equivalent to C-Bu-t)(12)(+) (abbreviated as Ag-15) nanocluster and its electrocatalytic properties toward CO2 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 CO2 in the air and spontaneously self-assembled into one-dimensional linear material during the crystal growth process. Furthermore, Ag-15 can convert CO2 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 equivalent to C-Bu-t)(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.