纳米固体酸S2O82-/Fe2O3催化合成马来酸二己酯

用S2 O2 -8 浸渍Fe2 O3 并焙烧制得了比SO2 -4/Fe2 O3 催化活性更强的固体超强酸S2 O2 -8/Fe2 O3 。通过马来酐与正己醇的酯化反应考察了催化剂的活性 ,对所合成的催化剂的结构用XRD和TEM进行了表征。结果表明 :S2 O2 -8/Fe2 O3 的催化作用明显高于SO2 -4/Fe2 O3 ;对于给定的反应 ,用NH3 ·H2 O作Fe2 O3 沉淀剂、用0 .2 5mol/L的 (NH4) 2 S2 O8浸渍Fe2 O3 15min ,在 5 5 0℃焙烧 3h时可制得较高活性的纳米级催化剂S2 O2 -8/Fe2 O3 ;其晶形为α Fe2 O3 ;有较好的重复使用性 ;它能代替硫酸、对甲苯磺酸用于催化马来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 S2O28-/Fe2O3 CATALYST

The solid super acid catalyst S 2O 2- 8/Fe 2O 3 (PSF) with higher activity than SO 2- 4/Fe 2O 3 was pre-pared by impregnating Fe 2O 3 with peroxyodisulfate and calcination. Its catalytic activity was examined by the synthesis of dihexyl maleate and its structure was characterized by RXD and TEM. The optimal conditions for preparing PSF were obtained as follows: Fe 2O 3 precipitant NH 3·H 2O, concentration of (NH 4) 2S 2O 8 0.25 mol/L, impregnation time 15 min, calcination temperature 550 ℃, calcination time 3 h, the obtained PSF is nanometer grade, its crystal corresponds to α-Fe 2O 3. Compared with sulfuric acid and p-toluene sulfonic acid catalysts, the dihexyl maleate prepared by PSF under the optimal conditions were colorless, and the PSF could be used repeatedly.