活性炭负载固体酸催化合成柠檬酸三丁酯

Synthesis of tributyl citrate catalyzed by active carbon supported solid acid

制备了11种活性炭负载的固体酸催化剂,对这类负载型催化剂催化柠檬酸与正丁醇酯化合成柠檬酸三丁酯的反应进行了考察,筛选出了几种高活性固体酸催化剂。进一步以负载型固体酸NaHSO4/C为催化剂,考察了催化剂用量、反应时间、醇酸物质的量比和反应温度等因素对酯化反应的影响,得出了最佳反应条件:催化剂用量5 mol%,酸醇摩尔比4.5∶1,反应温度为140℃,反应时间为3.0 h,酯化率可达到98%以上。最后对催化剂的分离、回收、循环使用以及再生方法进行了研究,催化剂使用5次仍可保持较高的催化活性,通过喷洒补加NaHSO4,即可使催化剂恢复催化活性,实现再生。

11 Examples of active carbon supported solid acid catalysts were prepared. The catalytic activity of this type of solid acid catalysts in the synthesis of tributyl citrate was explored and several catalysts with highly catalytic efficiency were obtained. Using NaHS04/C as catalyst, the esterification of citric acid and n-butyl alcohol was investigated. The effects of catalyst loading, the ratio of citric acid and n-butyl alcohol ,reaction time and reaction temperature were studied via single-factor experiments and the optimum reaction conditions were obtained ： with 5 tool% NaHSO4/C and 4. 5 equiv of n-butyl alcohol, conducted the reaction for 3.0 h at 140 ~C,the final tributyl citrate could be obtained in 98% yield. In addition, the catalyst could be seperated from the reaction mixture very easily,which could be used for many times without obvious decreasing of the reaction yield. The catalytic activity of catalyst could be recovered simply through the adding of NaHSQ.