以30%过氧化氢为氧化剂,考察了以杂多酸为催化剂氧化环己烯过程中离子液体的作用,讨论了离子液体种类和用量对反应的影响.结果表明,离子液体的加入顺序不同,其在催化过程中所起的作用不同.在反应条件为n(环己烯):n(过氧化氢):n(磷钨酸):n([(CH2)4SO3H-Py][HSO4])=1:4.4:0.28:0.56,在回流温度下反应8h时,己二酸收率可达到84.9%。该催化剂体系可循环使用.
Heteropoly acids (HPAs) are very attractive since their acidic and redox properties can be controlled at atomic or molecular levels. Among various HPAs structural classes, the Keggin-type HPAs containing tungstate and molybdenum have been widely employed not only for oxidation of organic substrates but also for many acid-catalyzed reactions due to their strong oxidizing ability and acid strength. Selective oxidation of lower hydrocarbons is of fundamental and technological interest because it provides a potential route to effectively transform lower hydrocarbon to higher, valueadded chemicals.