固体超强酸SO_4^(2-)/TiO_2-SiO_2催化合成马来酸二辛酯

Synthesis of Dioctyl Meleate in the Presence of Solid Super Acid SO_4^(2-)/TiO_2-SiO_2 Catalyst

用H2 SO4浸渍钛硅复合氧化物 ,制得固体超强酸SO2 -4/TiO2 -SiO2 ,考察了催化剂对马来酸酐与正辛醇的酯化反应的催化作用及其制备条件对催化剂活性的影响 ,并与硫酸、对甲苯磺酸的催化效果比较。结果表明 :对于给定反应 ,当n(Ti)∶n(Si)为 15∶1、用浓度 0 .6mol/L的硫酸浸渍 8h、在 5 5 0℃下焙烧 3h时制得的催化剂SO2 -4/TiO2 -SiO2 具有最高的催化活性 ;用以催化马来酸酐和正辛醇的酯化反应 ,可得无色透明的酯化产物 ,3h内酯化率达 99.1% ;较SO2 -4/TiO2 催化剂的酯化率提高了约 6 %

Solid super acid catalyst of SO 2- 4/TiO 2-SiO 2 type is prepared which showed more active than solid super acid catalyst of SO 2- 4/TiO 2 type in the synthesis of dioctyl maleate.The optimal conditions for preparation of the catalyst SO 2- 4/TiO 2-SiO 2 were obtained:mole ratio of titanium to silicon=15∶1,concentration of H 2SO 4=0.6?mol/L,impregnation time=8?h,calcination temperature=550?℃,calcination time=3?h.In comparison with sulfuric acid and p -methylbenzenesulfonic acid,the catalyst SO 2- 4/TiO 2-SiO 2 prepared under the optimal conditions had splendid catalytic activity with a yield of dioctyl meleate 99.1%,5% over that with catalyst of SO 2- 4/TiO 2 type under the same conditions.