固化SO3H-功能化离子液体新材料催化合成油酸甲酯

Esterification of methanol with oleic acid catalyzed on SiO2-IL by immobilization of SO3H-functionalized ionic liquid

摘要:

以1，3-丙烷磺内酯和巯基改性纳米二氧化硅球为原料，采用化学键合接枝法获得固化SO3H-功能化离子液体的酸催化材料(SiO2-IL)。采用NMR、FTIR和热分析方法对SiO2-IL的结构和热稳定性进行了表征。考察了SiO2-IL在油酸与甲醇酯化反应中的催化活性，经分析比较发现离子液体自身所具有的酸性以及固化过程中化学键合接枝程度均对其催化性能有所影响，并对反应工艺条件进行了优化。结果表明，在反应温度60 ℃、n(甲醇):n(油酸)=12:1、m(SiO2-IL):m(油酸)=0.09:1.00、反应时间5 h条件下，油酸甲酯收率最高为94%，催化材料经重复使用6次后，油酸甲酯收率仍可达74%。

Abstract:

One acidic solid catalyst (SiO2-IL) was successfully synthesized through immobilization of SO3H-functionalized ionic liquid by chemical bonding grafting, using 1, 3-propane sultone and thiolated nano-silicon dioxide as raw materials. The structure and thermal stability of the catalytic materials were characterized by NMR, FTIR and TG. Esterification of methanol with oleic acid was carried out by using this solid acidic catalyst. We find that the acidity of SO3H-functionalized ionic liquid and the stability of chemical bonding grafting are the key points and reasons to decide the catalytic performance of the solid catalyst. Moreover, the reaction conditions of reaction temperature, reaction time, molar ratio of reactants and the catalyst amount were optimized. The results show that under the optimized reaction conditions of 60 ℃, n (methanol):n (oleic acid)=12:1, 5 h, m (cat.):m (oleic acid)=0.09:1.00, the yield of methyl oleate was 94%. After reusing this acidic solid catalyst 6 times, the yield of methyl oleate still can be over 74%.