Ga2O3/凹凸棒石复合催化剂的制备和肉桂酸环己酯的催化合成

Preparation of Ga2O3/Palygorskite Composite Catalyst and Synthesis of Cyclohexyl Cinnamate

摘要:

采用浸渍法由凹凸棒石负载氧化镓(Ga2O3)制备了Ga2O3/凹凸棒石复合催化剂。用IR、XRD、BET、TEM等对催化剂结构进行了表征，并通过肉桂酸环己酯的合成，对催化剂制备条件、催化活性和反应动力学特性进行了考察。结果表明，催化剂的最佳制备条件是Ga2O3负载量为催化剂总质量的10 %，焙烧温度450 ℃；在肉桂酸环己酯合成过程中，当n(肉桂酸):n(环己醇)=1:4.5(其中肉桂酸0.02 mol)，催化剂用量0.5 g，反应温度130 ℃，反应时间70 min时，产品平均酯化率为95.0 %，催化剂经5次重复使用，酯化率仍达81.5 %；反应为准二级反应，表观活化能为90.78 kJ/mol，130 ℃时反应速率常数为1.03×10-2 L/(mol•min)。

Abstract:

Ga2O3/palygorskite composite catalyst was prepared by an impregnation method with palygorskite loading gallium oxide(Ga2O3), the structure of catalyst was characterized by means of IR, XRD, BET and TEM. The preparation conditions and catalytic activity of catalyst were investigated. The results indicated that the suitable preparation conditions of catalyst were Ga2O3 loading at 10 %, and calcination temperature 450 ℃. The average esterification rate was 95.0 % under the following conditions for synthesis of cyclohexyl cinanmate: n(cinnamic aicd):n(cyclohexanol)=1:4.5(cinnamic aicd was 0.02 mol), catalyst amount was 0.5 g, heat at 130 ℃ for 70 min. It could reach to 81.5 % while used for 5 times. It's a second-order reaction, the apparent activation energy was 90.78 kJ/mol, and the reaction rate constant was 1.03×10-2 L/(mol•min) in 130 ℃.