固体超强酸催化合成葡萄酒香料己酸正丁酯

摘要

利用四氯化锡、硅酸钠相互促进水解,制备了固体超强酸SO2-4/SnO2-SiO2催化剂,采用该催化剂催化正己酸与正丁醇的酯化反应合成葡萄酒香料己酸正丁酯,考察了催化剂制备条件和反应条件对酯化反应的影响以及催化剂的重复使用性能,并采用XRD,FTIR,TG分析等方法对催化剂进行了表征.实验结果表明,适宜的催化剂制备条件为:浸渍液为3 mol/L的硫酸、n(Sn)∶n(Si)=1∶8、焙烧温度500℃、焙烧时间3h;适宜的酯化反应条件为∶n(正丁醇)∶n(正己酸)=3.0∶1、催化剂用量0.5 g(基于0.1 mol正己酸)、回流反应2.0 h.在此条件下,酯化率可达99.0％.该催化剂的重复使用性能较好,使用5次时酯化率仍达80％以上.%Wine perfume butyl hexanoate was synthesized by esterification of hexanoic acid and w-butanol, using solid superacid SO2-4/SnO2--SiO2 as catalyst which was prepared by hydrolysis between stannic chloride and sodium silicate. The effects of the conditions of both the catalyst preparation and the esterification reaction on the esterification reaction were studied. The prepared catalysts were characterized by means of XRD, FTIR and TG. The results showed that under the appropriate conditions: impregnating solution 3 mol/L H2SO4, n(Sn) : n(Si) 1 : 8, catalyst calcination temperature 500 ℃, n(n-butyl alcohol) : n(hexanoic acid) 3.0 : 1, catalyst dosage 0.5 g(based on 0.1 mol hexanoic acid) and reflux for 2.0 h, the esterification rate could reach 99.0%. The esterification rate still kept above 80% after the catalyst was reused five times.