Mechanism and kinetic study of aerobic baeyer–villiger oxidation over a shaped Ce–Sn catalyst

Aerobic Baeyer-Villiger (B-V) oxidation reaction in the presence of aldehydes is a promising environmental-friendly synthetic route for the synthesizing ε-Caprolactone. Bimetallic oxides catalysts have been regarded as a highly efficient heterogenous catalysts to boost the oxidation capability of O 2 . However, the lack of kinetic parameters for the bimetallic oxide catalysts hinders the large-scale production of ε-Caprolactone. Herein, a shaped Ce–Sn bimetallic oxide was utilized as model catalysts for the mechanism and kinetic study of aerobic B-V oxidation reaction. The effects of the shaping process on the physical structure, surface valence state distribution, and microstructure morphology of the catalyst were systematically examined. The shaped catalyst exhibits a higher selectivity and conversion rate than the powder counterparts due to the increase of surface area. The reaction mechanism was investigated through stepwise experiments, radical trapping experiments, and electron paramagnetic resonance (EPR) spectroscopy. Based on the mechanism study results, a stepwise kinetic model involving peroxidation of benzaldehyde, B-V reaction and oxidation of benzaldehyde was established and demonstrated good predictive capability for aerobic B-V oxidation reaction. This study provides stepwise kinetic parameters for the aerobic oxidation of cyclohexanone in the presence of benzaldehyde, which would significantly promote the engineering application of the aldehyde/oxygen catalytic oxidation process.