SO_4^（2－）／Fe_2O_3－Al_2O_3的酯化催化活性与表面活性中心结

The Esterification Activities and the Structures of Surface Active Sites Over SO_4￣(2-)/Fe_2O_3-Al_2O_3

本文制备了ＳＯ_４^（２－）／Ｆｅ_２Ｏ_３－Ａｌ_２Ｏ_３系列固体酸催化剂，评价了各催化剂对醋酸与乙酸的酯化反应活性，该活性与由乙醇和苯探针分子的吸附热所标度的催化剂表面酸强度有较好关联。发现在７７３～８２３Ｋ温度下处理所得的ＳＯ_４^（２－）／Ｆｅ_２Ｏ_３－Ａｌ_２Ｏ_３催化剂的酸强度较大，催化活性较高．ＤＴＡ、ＩＲ和ＸＲＤ分析表明在该温度条件下处理所得的催化剂表面的硫酸根离子以剪式双配位于ｒ－Ｆｅ_２Ｏ_３之上。

The solid acid catalysts,SO_4￣(2-)/Fe_2O_3-Al_2O_3 series,were synthesized,The esterification activities of acetic acid and the adsorption heats of ethyl alcohol and benzen were inverstigated over the various catalysts. It was found that the catalysts calcined at 773～823K give rise to the maximum catalytic activities and the maximum adsorption heats. The SO_4￣(2-) anion species of chelating bidentete structure on r-Fe_2O_3,which is responsible for the generation of strong acidity,was proposed by using DTA IR and XRD methods.