SO4^2-／TiO2／膨润土催化合成氯乙酸异丁酯的研究

摘要

The solid superacid SO4^2-/TiO2/Bentonite was prepared by co-precipitation impregna- tion method with low-cost Bentonite. Isobutyl chloroacetate was synthesized from chloroacetic acid and isobutyl alcohol with solid superacid SO4^2-/TiO2/Bentonite as the catalyst. And the cat- alytic activity of SO4^2-/TiO2/Bentonite on esterification was studied. The effect of experimental reaction conditions, such as the molar ratio of acid to isobutyl alcohol, the reaction time, the choice of the water-taking agent, the amount of water-taking agent, the amount of catalyst, con- version and reusability of the catalyst on the esterification was studied. The optimum reaction conditions were found as follows： the amount of chloroacetic acid 0. 20mol, n（alcohol） ： n（acid）=1. 2 ： 1, the dosage of catalyst 0.5g, reaction time 3h, the dosage of cyclohexane 5mL, the yield of esteri- fication could reach 99.27 %. The catalyst showed that high activity after being reused for six times. The results showed the catalyst SO4^2-/TiO2/Bentonite had fine activity and could be used abroadly.%以低廉的膨润土为载体原料，采用浸渍法制备了固体超强酸SO4^2-／TiO2／膨润土；再以氯乙酸和异丁醇为原料，SO4^2-／TiO2／膨润土为催化剂，催化合成了氯乙酸异．丁酯。探讨了SO4^2-／TiO2／膨润土对酯化反应的催化活性，研究了原料醇酸摩尔比、反应时间、带水剂选择、带水剂用量、催化剂用量、催化剂重复使用性等反应条件对酯化反应的影响。结果表明：在氯乙酸用量为0．20mol，醇酸摩尔比为1．2：1，催化剂用量为0．5g，反应时间为3h，带水剂环已烷用量为5mL时，酯化率可达99．27％，催化剂重复使用6次后仍具有较高活性。表明SO4^2-／TiO2／膨润土催化剂具有稳定的催化活性。