Controllable Conversion of CO2 on Non-Metallic Gold Clusters

Gold nanoparticles in metallic or plasmonic state have been widely used to catalyze homogeneous and heterogeneous reactions. However, the catalytic behavior of gold catalysts in non-metallic or excitonic state remain elusive. Atomically precise Au-n clusters (n=number of gold atoms) bridge the gap between non-metallic and metallic catalysts and offer new opportunities for unveiling the hidden properties of gold catalysts in the metallic, transition regime, and non-metallic states. Here, we report the controllable conversion of CO2 over three non-metallic Au-n clusters, including Au-9, Au-11, and Au-36, towards different target products: methane produced on Au-9, ethanol on Au-11, and formic acid on Au-36. Structural information encoded in the non-metallic clusters permits a precise correlation of atomic structure with catalytic properties and hence, provides molecular-level insight into distinct reaction channels of CO2 hydrogenation over the three non-metallic Au catalysts.