LAUSR

Abstract The efficient selective oxidation of cyclohexane to cyclohexanone and cyclohexanol (KA-oil) under mild conditions remains one of the most challenging and interesting projects in catalytic chemistry. Here, photocatalytic oxidation of cyclohexane was carried out in acetonitrile (MeCN) solution of VOCl 2 under Xe lamp irradiation and pure O 2 atmosphere. The results show that VOCl 2 has high photocatalytic activity in pure MeCN solution, and a cyclohexane conversion of 17.8% with ca. 99% selectivity for KA-oil can be obtained after light irradiation of 4 h. It is worth noting that the use of hydrochloric acid as an additive can effectively enhance the photo-catalytic oxidation of cyclohexane, providing a cyclohexane conversion of 23.3%, which may be due to the important role of HCl in improving the light absorption, decreasing the oxidation-reduction potential of V 5+ /V 4+ and promoting the redox process of photocatalyst. The effects of photocatalyst concentration, hydrochloric acid addition amount, O 2 pressure and reaction time on photocatalytic performance were also studied. It was found that the optimization of these reaction conditions can further improve the conversion of cyclohexane and selectivity of KA-oil. A possible reaction mechanism for the photocatalytic oxidation of cyclohexane was proposed.