固体酸S_2O_8~(2-)/Fe_2O_3-SiO_2催化制备马来酸二己酯

在铁氧化物中引入硅的氧化物 ,并用S2 O82 -浸渍铁硅复合氧化物 ,制得固体酸催化剂S2 O82 -/Fe2 O3 SiO2 (Ⅰ )。用马来酸酐与正己醇的酯化反应考察了催化剂的活性。通过XRD和TEM分析 ,对催化剂的结构进行了表征。结果表明 ,Ⅰ的最佳制备条件为 :n(Fe)∶n(Si)为 5∶1、70℃陈化 3h ,2 0 0℃焙烧 2h、用 0 2 5mol/L的 (NH4) 2 S2 O8浸渍 3h、在 5 5 0℃下煅烧 6h ;Ⅰ的催化活性比S2 O2 -8/Fe2 O3 和SO2 -4/Fe2 O3 SiO2 更强 ,S2 O2 -8对Fe2 O3 SiO2 的促进作用明显高于SO2 -4;SiO2 的引入提高了催化剂的分散效果 ;有较好的使用重复性 ;它代替硫酸、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

Synthesis of dihexyl maleate over solid acid S2O82-/Fe2O3-SiO2 catalyst

Introduce silica into iron oxide to form a composite oxide of iron silicon,it is impregenated with persulfate,the solid acid catalyst S 2O 8 2- /Fe 2O 3 SiO 2 (I) is prepared.The catalytic activity of I is studied by the esterification of maleic anhydride and n hexanol.The structure of I is characterized by analysis of XRD and TEM.The results showed that the optimum conditions for preparing I were as below∶molar ratio of iron to silicon is 5∶1,ageing 3 h at 70 ℃,roast 2 h at 200 ℃,impregenating 3 h with 0.25 mol/L(NH 4) 2S 2O 8 and then calcinate 6 h at 550 ℃.The catalytic activity of I was more active than S 2O 8 2- /Fe 2O 3 and SO 2- 4/Fe 2O 3 SiO 2, the promoter action of S 2O 2- 8 was obviously high than SO 2- 4 for Fe 2O 3 SiO 2 .The dispersion effect of catalyst was increased by addition of SiO 2,its reusing properties were good.I can in place of surfuric acid and toluene p sulfonic acide for esterification of malcic anhydride and hexanol,the colorless and transparent product can be obtained.