改性活性炭负载三聚磷酸二氢铝催化合成苯甲醛乙二醇缩醛

采用硝酸改性活性炭后负载三聚磷二氢铝用于催化合成苯甲醛乙二醇缩醛,通过单因素实验考察醇醛摩尔比、催化剂用量及反应时间等因素对产品收率的影响,并采用正交实验获取较佳工艺条件。 结果表明,该催化反应中,当反应温度为110 ℃时,各因素对收率的影响顺序为:醇醛比>反应时间>带水剂加入量>催化剂用量。 优化反应条件为:苯甲醛0.2 mol,醇醛摩尔比2.5,反应时间75 min,催化剂加入量4%(占反应物总质量),带水剂加入量25 mL,苯甲醛乙二醇缩醛收率86.5%,催化剂经5次重复使用后收率仍大于86.0%。

Synthesis of Benzaldehyde Glycol Acetal Catalyzed by Aluminum Dihydrogen Tripolyphosphate Supported on Modified Activated Carbon

Benzaldehyde glycol acetal was synthesized by aluminum dihydrogen tripolyphosphate supported on nitric acid modified activated carbon. The effect of the molar ratio of alcohol to aldehyde, catalyst amount and reaction time on the yield were studied by single-factor experiments. Orthogonal design was used to obtain the optimized conditions for the synthesis of benzaldehyde glycol acetal. The results show that the three main influencing factors are in the order as follows: the molar ratio of alcohol to aldehyde>the reaction time>the quantity of water carrying agent>the quantity of catalyst. The optimal technical conditions are:temperature 110 ℃, benzaldehyde 0.2 mol, the molar ratio of alcohol to aldehyde is 2.5, reaction time 75 min, the quantity of catalyst 4%, water-carrying agent of cyclohexane 25 mL. Under these conditions, the yield of benzaldehyde glycol acetal is above 86.5%. The catalyst can be recycled for multiple uses and the acetal yield is 86.0% after five cycles.