H_6P_2Mo_9W_9O_(62)/TiO_2催化合成乙酸系列酯

Catalytic synthesis of series acetic ester with H_6P_2Mo_9W_9O_(62)/TiO_2

利用浸渍法以Ti O_2为载体负载Dawson型杂多酸H_6P_2Mo_9W_9O_(62)制备了催化剂H_6P_2Mo_9W_9O_(62)/TiO_2,采用XRD、IR等技术对其进行表征,以催化合成乙酸异戊酯为探针反应,系统考察了煅烧温度、杂多酸负载量、煅烧时间等制备条件对催化活性的影响。实验表明:制备催化剂的适宜条件为煅烧温度为200℃,杂多酸负载量为20%,煅烧时间为3h.利用该条件下制备的催化剂H_6P_2Mo_9W_9O_(62)/TiO_2合成乙酸异戊酯,正交实验结果表明,在n(异戊醇):n(乙酸)=1.6∶1.0,环己烷的用量为8.0 m L,催化剂H_6P_2Mo_9W_9O_(62)/TiO_2的用量为总质量的1.2%,反应时间为120 min的优化条件下,乙酸异戊酯平均收率可达74.8%.在最优反应条件下,乙酸乙酯的收率为56.3%,乙酸正丙酯的收率为74.6%,乙酸正丁酯的收率为76.1%,乙酸正戊酯的收率为90.1%.

A new environmentally amicable catalyst, H6P2Mo9W9O62/TiO2 was prepared. It was characterized by XRD, IR method, etc. Its catalytic activity was investigated with esterification of ethanoic acid and isoamyl alcohol as probing reaction. The preparation conditions of catalysts have also been investigated, that is, the calcining temperature is 200℃ the heteropoly acid load is 20%, the calcining time is 3h. The optimum reaction conditions are that the molar ratio of isoamyl alcohol to acetic acid is 1.6 ： 1.0 , the volume of cyclohexane is 8.0 mL , the mass ratio of the catalyst used to the reactants is 1.2%, and the reaction time is 120 min , the yield of isoamyl acetate is 74.8%. Under optimum reaction conditions, the yield of ethyl acetate is 56.3%, n -propyl acetate is 74.6%, butyl acetate is 76.1%, and n -amyl acetate is 90. 1%, respectively.