Baeyer–Villiger co-oxidation of cyclohexanone with Fe–Sn–O catalysts in an O2/benzaldehyde system

Abstract

Abstract Baeyer–Villiger (BV) oxidation of cyclohexanone to ε-caprolactone was studied by a co-precipitation method using Fe–Sn–O catalysts in an O2/benzaldehyde system. The effects of the Fe:Sn ratio, calcination temperature, calcination time, and reaction conditions on the catalytic performance were investigated. The catalysts present the best activity when it is prepared at a Fe:Sn ratio of 1:1, calcination temperature of 850°C, and calcination time of 5 h. Under these conditions, catalysts form a large number of small prisms, which result in a larger specific surface area and enhanced catalytic activity. The optimum reaction conditions for the synthesis of ε-caprolactone in the presence of the Fe–Sn–O catalyst are as follows: catalyst (0.12 g), 1,2-dichloroethane (30 mL), O2 flow rate of 25 mL min−1, cyclohexanone to benzophenone of 3:1, reaction temperature of 60°C, and reaction time of 5 h. The conversion of cyclohexanone and the average yield of ε-caprolactone are determined at 98.96% and 83.36%, respectively.