Research Of Catalytic Oxidation Of Cyclohexane To Cyclohexanone And Cyclohexanol

The reaction of oxidizing cyclohexane to cyclohexanone and cyclohexanol taking the cyclohexane as the material and hydrogen peroxide as oxidant with VPO catalysts was studied. The effect of synthesis conditions , solvent kind and amount, catalysts amount, oxidant amount, reaction temperature and reaction time were investigated in this text.In this work, the VPO catalyst and the Bi-promoted VPO catalyst were prepared, and the effects of reaction temperature, the addition of additives , P/V atomic ratio, pore-expanding agent, calcination temperature and reaction time on surface structure and catalytic performa- nce of catalysts were investigated by means of determination of average valence state of vanadium, XRD, IR and activity evaluation. It was indicated that the catalyst precursor prepared by reduction at 120℃, Bi/V=0.1, P/V=0.9, 12h consisted of (VO)2H4P2O7, which was converted mainly to VOPO4 at 400℃, showing better catalytic performance.The effects of the addition of differently promoters and the atomic ratio of Bi/V on the structure and performance of catalyst were studied by means of XRD and analysis of vanadium valence. It was showed that Bi is the best promoter and suitable atomic ratio of Bi/V was 0.1. The addition of Bi could adjust the proper ratio of V4+/V5+, thus increase the content of oxygen species and the activity of catalytic. The influence of process condition on the improved catalyst was investigated, and the optimized process condition were determined as: solvent acetone of 10mL, material cyclohexane of 0.6mL, catalyst of Bi-VPO 0.015g, 30% hydrogen peroxide of 3.0mL, the reaction temperature of 65℃, reaction time of 8h. Under above condition, the cyclohexane conversion was 81.4%, the cyclohexanone selectivity was 71.4% the cyclohexanone production rate can reach 58.0%, the cyclohexanone yield was 58.2% and 23.2% of cyclohexanol yield.