CuSO4／SiO2在合成苯甲醛甘油缩醛中的应用

通过溶胶-胶凝法和浸渍法制备了CuSO4／SiO2催化剂，用XRD、低温N2-吸附和NH3-TPD进行了表征，研究了CuSO4／SiO2在合成苯甲醛甘油缩醛上的催化性能，考察了催化剂的焙烧温度、CuSO4负载量、原料物质的量比、反应时间、环己烷体积等因素对产品收率的影响。结果表明：CuSO4高度分散在SiO2表面上形成中等酸强度、高表面积的中孔固体酸催化剂，并在苯甲醛和甘油的缩合反应中具有良好的催化活性和稳定性。催化剂制备的最佳条件为：焙烧温度550℃，CuSO4的负载量为15％，反应的最佳条件为：n（苯甲醛）：n（甘油）=1：1．1，催化剂质量为反应物总质量的1％，环己烷体积为10mL，反应时间2．0h。在最佳条件下，苯甲醛甘油缩醛的收率可达92．5％。

Synthesis of Benzaldehyde Glycerol Acetals Catalyzed by CuSO4/SiO2

CuSO4/SiO2 solid acid catalysts were prepared using sol--gel technique and impregnation method, and then characterized by XRD, low temperature N2- adsorption and NH3- TPD. The effects of calcination temperature of catalysts, CuSO4 loading, the molar ratio of benzaldehyde to glycerol, reaction time and amount of deaquation reagent on the synthesis yield were discussed. The results show that CuSO4 is highly dispersed over .surface of SiO2 to form mesoporous solid acid catalysts with medium acid strength and high specific surface. CuSO4/SiO2 showed good catalytic activities and stabilities in the condensation of benzaldehyde with glycerol to produce benzaldehyde glycerol acetals. The optimum preparation conditions are as follows： CuSO4 loadings 15%, and calcination temperature 550 ℃. The optimum reaction conditions are as follows.. molar ratio of benzaldehyde to glycerol is 1 ： 1.1, the weight percentage of catalyst in reaction mixture is 1 %, and volume of cyclohexane is 10 mL and reaction time 2 h. Under the optimum reaction conditions, the yield of benzaldehyde glycerol acetal can reach 92.5%.