铜交换磷钨酸高效催化合成异戊酸异戊酯

Highly Active Catalytic Synthesis of Isoamyl Isovalerate with Copper-Exchanged Phosphotungstic Acid as the Catalyst

以铜交换磷钨酸为催化剂,以异戊酸和异戊醇为原料,考察醇酸物质的量比、反应时间、催化剂用量和带水剂用量等因素对高效催化合成异戊酸异戊酯的影响,并通过响应面分析法优化酯化反应工艺.研究表明,铜取代的磷钨酸催化剂显示出较好的催化活性;在醇酸物质的量比为1.15∶1、催化剂用量为异戊酸质量的6.5%、带水剂用量为8 mL、反应时间为2.5 h的条件下,异戊酸异戊酯产率最高为98.1%,与模型预测值(98.8%)基本相符.优化条件下磷钨酸铜催化酯化反应的表观活化能E a=51.71 kJ/mol.

Isoamyl isovalerate was synthesized from isoamyl alcohol and isopentanoic acid,using copper-exchanged phosphotungstic acid as the catalyst.The effects of alcohol/acid molar ratio,reaction time,the amount of the catalyst and the water-carrying agent were also investigated.Meanwhile,response surface methodology(RSM)was used to optimize the operation conditions.Cu x H 3-x PW 12 O 40 showed good catalytic activity on the esterification of isoamyl alcohol with isopentanoic acid.Under the optimum conditions(n(isoamyl alcohol)∶n(isopentanoic acid)=1.15∶1,the amount of catalyst of 6.5%to acid,the amount of water-carrying agent 8 mL and reaction time 2.5 h),the yield of isoamyl isovalerate was as high as 98.1%,which was in close agreement with the value predicted by the mathematical model(98.8%).Moreover,a kinetic model for the esterification was established and evaluated under the optimized conditions.The apparent activation energy E a=51.71 kJ/mol.