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 potential owing to their fully exposed metal sites, alloying effects and unique electronic structures. However, the precise fabrication of bimetallic SLCs on a support remain challenging. Herein, a range of bimetallic M¹M²-SLCs (M¹M² = PdNi, PtCu, PtNi) with abundant and high-density diatomic alloy sites were precisely anchored onto 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. In particular, 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 the fully exposed structure of PdNi-SLCs and the cooperation between the Pd^δ−–Ni^δ+ bimetallic clusters with asymmetric charge distribution, in which Pd rapidly dissociated the Si–H bond of silane, while the adjacent Ni-mediated H₂O activation promoted the cleavage of the O–H bond, thereby facilitating the formation of silanol.