Ga_2(SO_4)_3/凹凸棒固体酸催化剂的制备及催化合成丁酸己酯

Preparation of Solid Acid Ga_2(SO_4)_3/Attapulgite Catalyst and Its Catalysis in the Preparation of Hexyl Butyrate

采用凹凸棒负载Ga2(SO4)3制备了Ga2(SO4)3/凹凸棒固体酸催化剂,用红外光谱、X射线衍射等对催化剂结构进行了表征,通过丁酸己酯的酯化反应考察了催化剂的制备条件、催化活性、重复使用性以及反应动力学。催化剂较优制备条件是:凹凸棒经1.1 mol/L硫酸溶液酸化处理,Ga2(SO4)3负载量占催化剂总质量的25%,焙烧温度350℃,焙烧时间2.0 h,在该条件下平均酯化率为98.1%。催化剂经5次重复使用后,酯化率仍不低于85%。反应动力学研究表明:反应级数为2,表观活化能为76.17 kJ/mol。

Solid acid Ga2 （SO4 ）3/attapulgite catalyst was prepared by loading Ga2 （SO4 ）3 on attapulgite. The structure of the catalyst was characterized by means of IR and XRD. The influence of preparation conditions on the catalyst and its catalytic activity and stability was investigated through the synthesis of hexyl butyrate. The kinetics characters of the catalytic reaction were discussed as well. The optimum preparation conditions of the catalyst were as follows ： sulfuric acid as impregnation liquid was 1.1 mo//L, the loading of Ga2 （SOn ）3 was 25% of the total amount of catalyst ,and the calcination was carried out at 350℃ for 2.0 h. The average yield was 98.1% ,and the yield was no less than 85% after the catalyst was reused for 5 times. The results of reaction kinetics show that it was the second order reaction, and the apparent activation energy was 76. 17 kJ/mol.