固体酸S_2O_8~(2-)/ZrO_2-SiO_2催化合成马来酸二辛酯

用S2O2-8浸渍锆硅复合氧化物,制得固体酸催化剂S2O2-8/ZrO2 SiO2。用马来酸酐与正辛醇的酯化反应考察了催化剂的活性,并与硫酸、对甲苯磺酸等催化剂的催化效果比较。结果表明:对于给定反应,S2O2-8对ZrO2 SiO2的促进作用明显高于SO2-4;当n(Zr)∶n(Si)为1∶6,用硝酸铵作硅酸钠的沉淀剂,用0.7mol/L的过硫酸铵浸渍12h,在550℃下焙烧3h制得的催化剂S2O2-8/ZrO2 SiO2具有最高的催化活性,用于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98.4%,较SO2-4/ZrO2 SiO2催化剂的酯化率提高了约18%。

Synthesis of dioctyl maleate by solid acid S_2O_8~(2-)/ZrO_2-SiO_2 catalyst

The solid acid catalyst S2O2-8/ ZrO2 SiO2 was prepared by impregnating zirconium silicon composite oxide with peroxodisulfate. The catalytic activity was studied in the esterfication of maleic anhydride to n octyl alcohol, and compared with sulfuric acid and p toluene sulfonic acid. The results showed that the promotion role of S2O2-8 was higher than of SO2-4.The catalyst S2O2-8/ ZrO2 SiO2 prepared under the optimal conditions,such as molar ratio of zirconia to silicon was 1∶6, concentration of (NH4)2S2O8 0.7 mol/L, impregnation 12 h,calcination at 550 ℃ for 3 h,had splendid catalytic activity for the synthesis of dioctyl maleate,and the product was colorless and transparent.The yield of dioctyl meleate was over 98.4% in reaction time 3 h,18% over than that with catalyst SO2-4/ZrO2 SiO2 under the same conditions.