The highly selective aerobic oxidation of cyclohexane to cyclohexanone and cyclohexanol (KA-oil) under benign and green conditions is still a challenging topic. In this work, V2O5@TiO2 catalysts were prepared by V species deposited on TiO2 (P25) and characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), and UV-vis diffuse reflectance techniques. The selective aerobic oxidation of cyclohexane was carried out over V2O5@TiO2 catalysts with oxygen as an oxidant under simulated light irradiation. The influences of solvents, metals and mass of V species deposited on TiO2, pressure of oxygen, and reaction time on the reaction were investigated. It was found that the V species deposited on the TiO2 surface was very efficient for the photocatalytic oxidation of cyclohexane under simulated solar light irradiation. More interestingly, the selectivity of the reaction in an acetonitrile/water mixed solvent was much higher than that in other solvents. Under the optimized conditions, the selectivity to KA-oil products could be nearly 100% at a cyclohexane conversion of 18.9%. The possible pathway for the catalytic reaction was proposed.

Efficient and greener oxidation of cyclohexene to 2-cyclohexene-1-one is an interesting topic. In this work, we prepared a series of Fe–Co doped graphitic carbon nitride (Fe–Co–g-C3N4) catalysts through simple impregnation and calcination methods. The catalysts were characterized by different techniques, such as transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), nitrogen adsorption–desorption measurement, powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The selective oxidation of cyclohexene to 2-cyclohexene-1-one was carried out in different solvents over the catalysts using molecular oxygen as an oxidant. The influence of supports, solvents, Fe/Co molar ratio in the catalysts, pressure of oxygen, reaction temperature and time of the reaction was investigated. It was revealed that the bimetallic Fe–Co–g-C3N4 catalysts were very efficient for the reaction. More interestingly, the selectivity of the reaction in water was much higher than that in other solvents. Under optimized conditions, the selectivity to 2-cyclohexene-1-one could reach 95% at a cyclohexene conversion of 36%. The Fe–Co–g-C3N4 catalyst could be reused at least four times without obvious loss of efficiency.

Efficient and greener oxidation of cyclohexene to 2-cyclohexene-1-one is an interesting topic. In this work, we prepared a series of Fe–Co doped graphitic carbon nitride (Fe–Co–g-C3N4) catalysts through simple impregnation and calcination methods. The catalysts were characterized by different techniques, such as transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), nitrogen adsorption–desorption measurement, powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The selective oxidation of cyclohexene to 2-cyclohexene-1-one was carried out in different solvents over the catalysts using molecular oxygen as an oxidant. The influence of supports, solvents, Fe/Co molar ratio in the catalysts, pressure of oxygen, reaction temperature and time of the reaction was investigated. It was revealed that the bimetallic Fe–Co–g-C3N4 catalysts were very efficient for the reaction. More interestingly, the selectivity of the reaction in water was much higher than that in other solvents. Under optimized conditions, the selectivity to 2-cyclohexene-1-one could reach 95% at a cyclohexene conversion of 36%. The Fe–Co–g-C3N4 catalyst could be reused at least four times without obvious loss of efficiency.