Monoterpenes etherification reactions with alkyl alcohols over cesium partially exchanged Keggin heteropoly salts: effects of catalyst composition
作者:Márcio José da Silva、Neide Paloma Goncalves Lopes、Sukarno Olavo Ferreira、Rene Chagas da Silva、Ricardo Natalino、Diego Morais Chaves、Milena Galdino Texeira
DOI:10.1007/s11696-020-01288-x
日期:2021.1
partially exchanged Keggin heteropolyacid (HPA) salts were prepared, characterized, and evaluated as solid catalysts in monoterpenes etherification reactions with alkyl alcohols. A comparison of the activity of soluble HPAs and their insoluble cesium salts showed that among three different Keggin anions the phosphotungstate was the most efficient catalyst. Assessments on the effects of the level of the protons
在这项工作中,铯部分交换的 Keggin 杂多酸 (HPA) 盐被制备、表征和评估作为与烷基醇的单萜醚化反应中的固体催化剂。可溶性 HPA 及其不溶性铯盐的活性比较表明,在三种不同的 Keggin 阴离子中,磷钨酸盐是最有效的催化剂。铯阳离子对质子交换水平影响的评估表明,Cs 2.5 H 0.5 PW 12 O 40 固体盐是最具活性和选择性的磷钨酸盐催化剂,可将β-蒎烯转化为α-松油基甲基醚。研究了主要反应参数如反应温度、时间、催化剂负载、底物性质(即醇和单萜)的影响。我们已经证明,催化剂中同时存在的铯离子和质子起着至关重要的作用,最佳摩尔比为 2.5-0.5。Cs 2.5 H 0.5 PW 12 O 40 盐在催化活性不损失的情况下得到有效回收和再利用。图形摘要