Evolution of Electrocatalytic CO2 Reduction Activity Induced by Charge Segregation in Atomically Precise AuAg Nanoclusters Based on Icosahedral M-13 Unit 3D Assembly

The precise self-assembly of building blocks at atomic level provides the opportunity to achieve clusters with advanced catalytic properties. However, most of the current self-assembled materials are fabricated by 1/2D assembly of blocks. High dimensional (that is, 3D) assembly is widely believed to improve the performance of cluster. Herein, the effect of 3D assembly on the activity for electrocatalytic CO2 reduction reaction (CO2RR) is investigated by using a range of clusters (Au8Ag55, Au8Ag57, Au12Ag60) based on 3D assembly of M-13 unit as models. Although three clusters have almost the same sizes and geometric structures, Au8Ag55 exhibits the best CO2RR performance due to the strong CO2 adsorption capacity and effective inhibition of H-2 evolution competition reaction. The deep insight into the superior activity of Au8Ag55 is the unique electronic structure attributed to the charge segregation. This study not only demonstrates that the assembly mode greatly affects the catalytic activity, but also offers an idea for rational designing and precisely constructing catalysts with controllable activities.