磷钨杂多酸盐催化苯甲醇选择氧化性能的研究

以溴化1-丁基-3-甲基咪唑盐（[Bmim]3Br）、1-（3-磺酸基）丙基-3-甲基咪唑盐（MIMPS）、1-（3-磺酸基）丙基吡啶盐（PyPS）和磷钨酸（H3PW12O40）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]3PW12O40显示较高的催化性能,在优化的反应条件下（苯甲醇10 mmol、H2O230 mmol、催化剂0.05 mmol、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。

Selective Oxidation of Benzyl Alcohol Using Dodecatungstophosphate as Catalyst

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) H2O2 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 3PW12O40 exhibited better catalytic performance.Under the optimal reaction conditions(benzyl alcohol 10 mmol,hydrogen 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.