Pt Single Atoms and Nanosized Clusters as Catalytic Reaction Platforms for Selective Hydrogenation Applications

The exploitation and design of high-efficiency catalysts have attracted extensive attention in the selective regulation of hydrogenation reactions; however, it remains a tremendous challenge currently. Herein, we report two kinds of nanosized Pt-based catalysts, including single-atom catalysts (SACs) and nanosized cluster catalysts (NCCs), anchored onto a CoAlOx support via the topotactic transformation of layered double hydroxides. The SAC (Pt1/CoAlOx) exhibits a >99% selectivity toward the hydrogenation of furfural (FAL) to furfuryl alcohol (FOL), while the NCC (Ptn/CoAlOx) shows a >99% selectivity for tetrahydrofurfuryl alcohol (THFOL) under a mild reaction condition (room temperature and a 0.1 MPa pressure of H2). Both in situ experiments and theoretical calculations reveal that the aggregation state (single atom or nanosized cluster) of Pt atoms influences the adsorption configuration of FAL, in which the adsorption of C═O occurs on Pt single atoms over Pt1/CoAlOx and the adsorption of both C═C and C═O occurs on continuous Pt atoms over Ptn/CoAlOx. The structure–selectivity relationship substantiates that metal ensemble size has an important effect on the adsorption structure of the reaction substrate and thus results in the different selectivity of the hydrogenation reaction.