Selective hydrogenation of 2-pentenal using highly dispersed Pt catalysts supported on ZnSnAl mixed metal oxides derived from layered double hydroxides

Abstract

A highly dispersed Pt catalyst supported on ZnSnAl mixed metal oxides (MMO), with Pt in single-atom and small nanoclusters, was produced by the induction of lattice-confined Sn sites in layered double hydroxides (LDHs) and used in the selective hydrogenation of 2-pentenal. Compared with the Pt/Al₂O₃, Pt–SnO_x/Al₂O₃ and MgSnAl-MMO supported Pt catalysts, the optimized ZnSnAl-MMO supported Pt catalyst gave a higher selectivity to 2-pentenol (82.2%) at 28.5% conversion of 2-pentenal. Based on catalytic evaluation results and catalyst characterization with XRD, Pyridine-IR, H₂-TPR, XPS, and HAADF-STEM, it was found that the combined effects of Sn and Zn species promoted the performance of the Pt catalyst by favoring the activation of the CO bond. In addition, due to the size effect and electronic effect on the Pt species, the highly dispersed Pt induced by the lattice-confined Sn sites in ZnSnAl-LDH enhanced the catalytic activity of Pt/Zn(1Sn)(Al)O/Al₂O₃ by 2.7 times compared with Pt–SnO_x/Zn(Al)O/Al₂O₃.