S2O2－8/Fe2O3-ZrO2-SiO2固体酸催化剂合成马来酸二己酯

在铁锆氧化物中引入硅的氧化物，并用S₂O^2－₈浸渍铁锆硅复合氧化物，制得较S₂O^2－₈/Fe₂O₃-ZrO₂（PSFZ）和SO^2－₄/Fe₂O₃-ZrO₂-SiO₂（SFZS）催化活性更强的固体酸催化剂S₂O^2－₈/Fe₂O₃-ZrO₂-SiO₂（PSFZS），研究获得最佳制备条件。用马来酸酐与正己醇的酯化反应考察了催化剂活性。XRD和TEM结果表明，制备的催化剂S₂O^2－₈对铁锆硅复合氧化物的促进作用明显好于SO^2－₄；SiO₂ 和Fe₂O₃的引入使催化剂呈现多孔结构，分散性好，其稳定性增加，催化活性提高；用该催化剂代替硫酸和对甲苯磺酸用于催化马来酸酐和正己醇的酯化反应，可得无色透明的酯化产物，3 h内酯化率达97.9%，分别比PSFZ和PSFZS催化剂提高约10%20%。

Synthesis of dihexyl meleate over S_2O_8~(2-)/Fe_2O_3-ZrO_2-SiO_2 solid acid catalyst

S_2O~(2-)_8/Fe_2O_3-ZrO_2-SiO_2 (PSFZS) solid acid catalyst was prepared by incorporating silica into iron zirconia and impregnating with peroxodisulfate, with higher activity for synthesis of dihexyl maleate than S_2O~(2-)_8/Fe_2O_3-ZrO_2 (PSFZ) and SO~(2-)_4/Fe_2O_3-ZrO_2-SiO_2 (SFZS). The optimum preparation condition for PSFZS was obtained. Activity of PSFZS was investigated for esterification of maleic anhydride and n-hexanol, and its structure characterized by XRD and TEM. The results showed that the promoting function of S_2O~(2-)_8 for Fe_2O_3-ZrO_2-SiO_2 was obviously higher than that of SO~(2-)_4. Incorporation of SiO_2 and Fe_2O_3 resulted in porous structure, better dispersion, increased stability and improved activity of PSFZS. For esterification of maleic anhydride and n-hexanol over PSFZS instead of sulfur acid and p-methylbenzene sulfonic acid, dihexyl meleate yield of 97.9% was obtained, 10% higher than that of PSFZ and 20% higher than SFZS.