摘要
传统方法合成羧酸酯通常用浓硫酸作催化剂,副反应多,产物分离困难,设备腐蚀严重.为克服这些缺点,张怀彬等采用了HZSM-5等硅铝分子筛催化合成羧酸酯.但AlPO_4分子筛是否具有催化酯化反应的功能,至今未见文献报道.我们以自制的新型AlPO_4分子筛CHNUAP-1作催化剂,对其催化合成丙酸戊醋的活性及反应条件进行了考察.
Amyl propionate was synthesized by the esterification of K-pentanol with propionic acid using novel aluminophosphate molecular sieves as catalysts. Under the following conditions: AlPO4 molecular sieve/propi-onic acid=0.6g/mol, the molar ratio of n-pentanol/propionic acid=1.1:1, the amount of cyclohexane used = 5.0ml/mol propionic acid , 145-150℃ and 4.5 hours, the yield of amyl propionate was over 80.0%. The influence of the preparation method of AlPO4 molecular sieves on the catalytic activity was also studied. Essentially the activity had nothing to do with the crystal structure of the AlPO4 molecular sieves. AlPO4 supported with Zn2+ or P decreased slightly the activity.
