改性钒磷氧化物催化剂液相选择性氧化环己烷

LIQUID PHASE SELECTIVE OXIDATION OF CYCLOHEXANE WITH MODIFIED VPO CATALYSTS

用浸渍法制备了Fe,Co,Ni,Bi改性的钒磷氧化物(VPO)催化剂,对催化剂进行了XRD和SEM表征,用氧化还原滴定法测定了不同晶相催化剂中钒的平均价态,并以环己烷为原料、H_2O_2,为氧化剂,考察了金属改性对VPO催化剂液相催化氧化环己烷合成环己酮性能的影响。结果表明,几种催化剂对液相催化氧化环己烷合成环己酮反应的催化活性由大到小的顺序为:Bi-VPO>Fe-VPO>Ni-VPO>Co-VPO>VPO。在环己烷用量0.6 mL、丙酮用量10mL、催化剂Bi-VPO加量0.015g、H_2O_2,用量3mL、65℃、反应时间8h的条件下,环己烷转化率为81.4%,环己酮和环己醇收率分别为58.2%和23.2%。

Four vanadium phosphorus oxides （VPO） catalysts modified by Fe, Co, Ni and Bi respectively were prepared and characterized by XRD and SEM. The average oxidation values of vanadium in these catalysts were determined by oxidation-reduction titration. The synthesis of cyclohexanone from cyclohexane using hydrogen peroxide as oxidant over various modified VPO catalysts was carried out in the liquid phase to compare the catalytic performance of these catalysts. Test results showed that the catalytic activities for cyclohexane to cyclohexanone of these catalysts from high to low were in the order of Bi-VPO〉Fe-VPO〉 Ni-VPO 〉 Co-VPO 〉VPO. Under the conditions of a cyclohexane amount of 0.6 mL, an acetone amount of 10 mL, a Bi-VPO catalyst dosage of 0.015 g, a hydrogen peroxide amount of 3 mL, a reaction temperature of 65 ℃ and a reaction time of 8 h, the conversion of cyclohexane reached 81.4%, the yields of cyclohexanone and cyclohexanol were 58.2% and 23.2%, respectively.