Design and Synthesis of Single-Atom Layer Bimetallic Clusters for Dehydrogenative Silylation of Water and Alcohols

Abstract

Single-atom layer clusters (SLCs) have demonstrated high catalytic potentials owing to the fully exposed metal sites, alloying effects and unique electronic structures. However, it is challenging for the precise fabrication of bimetallic SLCs on a support. Herein, a range of bimetallic M1M2-SLCs (M1M2 = PdNi, PtCu, PtNi) with abundant and high-density diatomic alloy sites were precisely anchored onto the carboxyl-functionalized carbon nanotubes (CNTs). Catalytic results showed that the resultant composite of PdNi-SLCs/CNTs was efficient for catalytic dehydrogenative silylation of H2O and alcohols, giving rise to diverse silanols and alkoxysilanes, respectively, in high yields. Especially, the turnover frequency and maximum turnover number of PdNi-SLCs/CNTs-catalyzed dehydrogenative silylation of water were up to 187 s–1 and 964,737 based on Pd, respectively. Reaction mechanism studies revealed that the high catalytic performance was primarily attributed to fully exposed structure of PdNi-SLCs and the cooperation between the Pdδ- – Niδ+ bimetallic clusters with asymmetric charge distribution, in which Pd rapidly dissociated the Si-H bond of silane, and meanwhile the adjacent Ni-mediated H2O activation promoted the cleavage of O–H bond, thereby facilitating the formation of silanol.