负载型离子液体催化酯化法合成三醋酸甘油酯

研究了以磺酸咪唑基离子液体催化甘油和醋酸通过直接酯化法合成三醋酸甘油酯反应,结果表明,(n-Bu-SO_3H)MIm]HSO_4]离子液体催化性能最好。采用浸渍法将其固载在SiO_2的表面,利用FT-IR对催化剂结构进行了表征,考察反应工艺条件对甘油转化率和三醋酸甘油酯选择性的影响,结果表明,在催化剂用量8%,醋酸与甘油物质的量比6∶1,110℃条件下反应8.0 h,甘油转化率可达到97.2%,对应的三醋酸甘油酯选择性可达21.2%。回收的催化剂经重复使用4次,反应体系中甘油转化率和三醋酸甘油酯选择性无明显下降。

Synthesis of glycerol triacetate by esterification over supported ionic liquids catalysts

Herein,a series of imidazolium sulfonate ionic liquid catalysts were applied to the synthesis of glycerol triacetate from glycerin and acetic acid.Meaningfully,the results showed that (n-Bu-SO₃H)MIm]HSO₄]had the best catalytic performance.Additionally,(n-Bu-SO₃H)MIm]HSO₄]/SiO₂ (BHS) was prepared by a wet impregnation method and the structure was characterized by FT-IR.Meanwhile,the effects of reaction conditions on glycerol conversion and glycerol triacetate (GTA) selectivity were investigated.Experimental results showed that glycerol conversion of 97.2%,GTA selectivity of 21.2% were obtained when catalyst mass fraction was 8% and acetic acid/glycerol molar ratio was 6∶1 at reaction temperature of 110 ℃ for 8 h.Significantly,recovered catalyst had excellent catalytic activity and reusability,after four successive runs,glycerol conversion and GTA selectivity had no obvious change.