Photocatalytic Oxidation of Cyclohexane into Cyclohexanol and Cyclohexanone over TiO2/TS-1 System by Molecular Oxygen

摘要

C-H bond activation leading to catalytic oxidation of these hydrocarbons under mild conditions is one of the most challenging chemical problems, in addition to being of great practical importance. Dioxygen(O2) is clearly the most desirable oxidant due to its ready availability and high reduction potential.Many papers on oxidation of alianes in mild conditions by molecular oxygen in presence of coreductants such as CO and H2 have been compiled. Herein, we describe a system which achieves selective oxidation of cyclohexane into cyclohexanol by molecular oxygen under mild condition with cyclohexanol selectivity nearly 50%. The system involves a photocatalyst TiO2, a selective catalyst titanium silicalite-1 (TS-1). The TiO2 serves as photocatalyst for active oxygen species formation from oxygen uptake under UV irradiation, titanium silicalite serves as selective oxidation catalyst for cyclohexane oxidation into cyclohexanol.