Abstract: Three dodecatungstophosphates were prepared from 1-butyl-3-methylimidazolium bromide, 1-(3-sulfonic group) propyl-3-methylimidazolium, 1-(3-sulfonic group) propyl pyridinium and 12-tungstophosphoric acid. The IR and XRD results of three dodecatungstophosphates demonstrated that all of them contain typical heteropolyanions. Selective oxidation of benzyl alcohol to benzaldehyde with 30%(mass fraction) H2O2 as oxidant was carried out in the absence of organic solvents, phase-transfer catalysts and additives. Effects of different catalysts were studied and reaction conditions were optimized. It is found that 1-butyl-3-methylimidazolium dodecatungstophosphates ［Bmim］3PW12O40 exhibited better catalytic performance. Under [KG*4]the [KG*4]optimal [KG*4]reaction [KG*4]conditions(benzyl [KG*4]alcohol 10 mmol, hydrogen [KG*4]peroxide 30 mmol, catalyst 0.05 mmol, reaction temperature 85 ℃, reaction time 3 h), the conversion of benzyl alcohol was 79.6% and the selectivity of benzaldehyde could reach 95.6%. The catalysts are also proven to have good recycling capability. 

Key words: 12-phosphotungstic acid, Benzyl alcohol, Catalytic oxidation, Benzaldehyde

摘要： 以溴化1 -丁基-3 -甲基咪唑盐([ Bmim] 3 Br)、1 -(3 -磺酸基)丙基-3-甲基咪唑盐(MIM PS)、1 -(3-磺酸基)丙基吡啶盐(PyPS)和磷钨酸(H3 PW12O40)为原料制备了3 种磷钨杂多酸盐催化剂, 并用IR 和XRD 进行了表征。结果表明, 3 种催化剂均具有典型的杂多阴离子结构。在无有机溶剂、相转移催化剂和添加剂的条件下, 将其应用于H2O2(质量分数30 %)作氧化剂催化苯甲醇合成苯甲醛的反应中, 考察了不同催化剂和反应因素对苯甲醇氧化的影响。结果表明:1 -丁基-3 -甲基咪唑磷钨杂多酸盐[ Bmim] 3 PW12O40 显示较高的催化性能, 在优化的反应条件下(苯甲醇10 mmo l、H2O2 30 mmo l、催化剂0 .05 mmo l、反应温度85 ℃、反应时间3 h), 苯甲醇的转化率和苯甲醛的选择性分别为79.6 %, 95.6%, 且该催化剂重复使用情况良好。

关键词: 磷钨酸 , 苯甲醇 , 催化选择氧化 , 苯甲醛