Influence of DETA on the Tin Promotion of Mesoporous Sn–Ti Catalysts for Cyclohexanone Oxidation by Molecular Oxygen

Abstract

A series of Sn–Ti(n)–DETA catalysts were prepared by a simple EISA method assisted by post-treatment of diethylenetriamine (DETA) solution, and several characterization techniques, including XRD, N2 sorption, Raman, ICP, UV–Vis DRS, pyridine-adsorbed IR, SEM, and TEM, were adopted to investigate their physical and chemical properties. The influence of DETA on the tin incorporation promotion of mesoporous Sn–Ti catalysts and their catalytic performance in the B–V oxidation of cyclohexanone by molecular oxygen were also studied. The mesopores with higher surface area and larger pore volume can be kept well when the weight percent of tetrahedrally incorporated tin species would be promoted up to 21% owing to the stronger alkalinity and more primary amine of the DETA molecule resulting in higher Lewis acidity. The cyclohexanone conversion of 95.5% and caprolactone selectivity of 96.8%, respectively, over Sn–Ti(21)–DETA catalyst were obtained, and it shows good catalytic stability even after reused for 5 times.