高岭土复合型固体酸催化合成异丁酸丁酯

Synthesis of Butyl-isobutyrate with Composite Kaolin Solid Acid as Catalyst

以质量比为1∶9∶20的硝酸铈铵、高岭土和SnCl4·5H2O制备了高岭土复合型固体酸催化剂,制备条件为70℃水浴中陈化12h,促进剂H2SO4浓度为2.0mol/L,浸渍12h,350℃焙烧3h,并采用XRD对催化剂进行了表征。该催化剂用于异丁酸与正丁醇的酯化反应合成了异丁酸丁酯,考察了带水剂种类、催化剂用量、异丁酸与正丁醇的摩尔比、反应时间及催化剂重复使用性等因素对酯收率的影响。结果表明,该催化剂具有催化活性高、易分离回收、成本低、重复使用性好等优点。适宜反应条件为醇酸摩尔比为1.7、催化剂用量为反应物总质量的2.0%、反应时间100min,酯收率为96.5%。该催化剂重复使用6次,其酯收率仍接近80%。

Butyl-isobutyrate was synthesized from isobutyric acid and n-butanol with a new composite solid acid catalyst. Preparing conditions of the catalyst were： mass ratio of ammonium ceric nitrate to kaolin to SnCl4· 5H2O 1 ： 9 ： 20, ageing timel2h at 70℃, concentration of sulfuric acid 2.0mol/ L, impregnation time12h, and calcination at 350℃ for 3h. The catalyst was characterized by XRD. As using synthesis of butyl-isobutyrate, effects of type of water entrainer, catalyst dosage, mole ratio of butanol to isobutyric acid and reaction time on the yield of butyl-isobutyrate were all studied. Under the optimal conditions： mole ratio of butanol to isobutyric acid 1.7, reaction time 100 min, and mass fraction of catalyst in all of reaction system 2.0%, the yield is 96.5%. The catalyst also has excellent stability. When it was reused for six times, the yield could approach 80%. The composite solid acid catalyst takes advantages of low cost, highly active, non-polluting and reusable.