One-step preparation of Pt/Ag nanoclusters for CO2 transformation

Abstract

Structurally precise metal nanoclusters with a facile synthetic process and high catalytic performance have been long pursued. These atomically precise nanocatalysts are regarded as model systems to study structure-performance relationships, surface coordination chemistry, and the reaction mechanism of heterogeneous metal catalysts. Nevertheless, the research on silver-based nanoclusters for driving chemical transformations is sluggish in comparison to gold counterparts. Herein, we report the one-step synthesis of Pt/Ag alloy nanoclusters of [PtAg₉(C₁₈H₁₂Br₃P)₇Cl₃](C₁₈H₁₂Br₃P), which are highly active in catalysing cycloaddition reactions of CO₂ and epoxides. The cluster was obtained in a rather simple way with the reduction of silver and platinum salts in the presence of ligands in one pot. The molecular structure of the titled cluster describes the protection of the Pt-centred Ag₉ crown by the shell of phosphine ligands and halides. Its electronic structure, as revealed by density function theoretical calculations, adopts a superatomic geometry with 1S²1P⁶ configuration. Interestingly, the cluster displays high activity in the formation of cyclic carbonates from CO₂ under mind conditions.