Evolution of Electrocatalytic CO₂ Reduction Activity Induced by Charge Segregation in Atomically Precise AuAg Nanoclusters Based on Icosahedral M₁₃ Unit 3D Assembly

Abstract 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 M₁₃ 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 H₂ 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.