Research In Cyclohexanone Synthesis By Catalytic Oxidation

In this paper, three catalysts were successfully prepared, and which were applied to catalyze selective oxidation of cyclohexane to cyclohexanone and cyclohexanol using oxygen. These catalysts were characterized by a series of methods, the effects of catalyst preparation conditions and oxidation reaction parameters on their catalytic performances were investigated in cyclohexane oxidation to cyclohexanone and cyclohexanol using oxygen as the oxidant.A catalyst comprising Cu/HZSM-5 molecular sieves was prepared by ion exchange and characterized by XRD, BET, ICP, FT-IR and TG/DTA. Crystallization of CuO occurs between 300 and 400℃. The presence of various ligand bonds between the support and the copper species scattered in the molecular sieve matrix. Cu/HZSM-5 subjected to ion exchange with 10 % copper nitrate solution at 80℃for 8 h and calcination at 600℃exhibited the best performance. Using 0.5 mL of cyclohexane,10 mL of acetonitrile, 4 mL of hydrogen peroxide and 0.03 g of catalyst at a reaction temperature of 65℃for 6 h, the cyclohexane conversion was 43.1 % and the total selectivity to cyclohexanol and cyclohexanone was 95.7 %.New type composite catalyst of V₂O₅ comprising Co-Mo/V₂O₅ was prepared by immersion method and characterized by XRD, BET and FT-IR. CoMoO4 and CoMoO3 are the incomplete crystalline phase complex metal oxides which have catalytic activity, demonstrating that there is interaction between pure V₂O₅ and doped components. Co-Mo/V₂O₅ subjected to immersion method with 5 % Co and 20 % Mo mixed solution at room temperature for 1 h and calcination at 600℃exhibited the best performance. Using 0.5 mL of cyclohexane, 3 mL of hydrogen peroxide and 30 mg of catalyst at a reaction temperature of 55℃for 3 h, the cyclohexane conversion was 39.1 % and the total selectivity to cyclohexanol and cyclohexanone was 100 %.CuPMo/V₂O₅ catalyst was prepared by immersion method and characterized by XRD, BET and FT-IR. The doping components had no obvious effect on the structure of V₂O₅ and were highly dispersed on the surface of V₂O₅. CuPMo/V₂O₅ subjected to immersion method at room temperature for 12 h and calcination at 320℃exhibited the best performance. Using 0.5 mL of cyclohexane, 3 mL of hydrogen peroxide and 30 mg of catalyst at a reaction temperature of 65℃for 3 h, the cyclohexane conversion was 53.6 % and the total selectivity to cyclohexanol and cyclohexanone was 100 %.