Ga2(SO4)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 Ga2(SO4)3/Attapulgite Catalyst and Catalysis of Hexyl Butyrate

摘要:

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2.5 h。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。

Abstract:

Solid acid Ga2(SO4)3/attapulgite catalyst was prepared by loading Ga2(SO4)3 on attapulgite. The structure of catalyst was characterized by means of IR and XRD. The preparation conditions on catalyst, catalytic activity and stability of catalyst were investigated by synthesis of hexyl butyrate. The kinetics characters of catalytic reaction were discussed as well. The optimum preparation conditions on catalyst were as follow: sulfuric acid as impregnation liquid was 1.1 mol/L, the loading of Ga2(SO4)3 was 25% in catalyst, calcinated at 350 ℃ for 2.5 h. Under the optimum esterificaton conditions, the average yield was 98.1 %. the yield was no less than 85 % after used for 5 times. The results of reaction kinetics showed that it was the second order reaction, and the apparent activation energy was 76.17 kJ/mol.