Dawson型磷钼钒杂多酸催化环己醇氧化制备环己酮

Preparation of Cyclohexanone Through Catalytic Oxidation of Cyclohexanol over Dawson Type P-Mo-V Heteropolyacid

合成了 Dawson 型磷钼钒杂多酸,采用傅里叶变换红外光谱和 X 射线衍射等方法表征了磷钼钒杂多酸的结构;以环己醇为原料、H_2O_2为氧化剂、磷钼钒杂多酸为催化剂制备了环己酮,考察了催化剂的钒含量、溶剂的类型和反应条件(催化剂用量、H_2O_2用量、反应时间和反应温度)对环己醇氧化反应的影响。实验结果表明,钒含量适中的 H_8P_2Mo_(16)V_2O_(62)催化剂活性最高,乙腈是该反应的优质溶剂。环己醇催化氧化制备环己酮的适宜反应条件为:环己醇0.05 mol、H_8P_2Mo_(16)V_2O_(62)催化剂用量0.25 mmol、质量分数30%的 H_2O_2溶液用量20 mL、反应时间2 h、反应温度80℃、乙腈用量10 mL;在此条件下,环己醇转化率为59.3%,环己酮选择性为73.5%。

Cyclohexanol was oxidized into cyclohexanone over Dawson type P-Mo-V heteropolyacid catalyst with H2O2 as oxidant. The prepared heteropolyacid was characterized by means of FTIR and XRD. Effects of solvent type, vanadium content in P-Mo-V heteropolyacid, catalyst dosage and H2O2 dosage, reaction temperature and reaction time on oxidation of cyclohexanol were investigated. The H8P2MO16 V2O62 with moderate content of vanadium is the highest in activity and acetonitrile is an ideal solvent. Under optimal conditions： cyclohexanol 0.05 mol ,H8P2MO16 V2O62 catalyst 0. 25 mmol, 30% （w） H2O2 solution 20 mL, reaction time 2 h, reaction temperature 80 ℃ and 10 mL acetonitrile as solvent, conversion of cyclohexanol and selectivity to cyclohexanone are 59.3 % and 73.5% respectively.