环境友好催化剂TiSi W_(12)O_(40)/TiO_2的制备及其催化性能研究

Preparation and Catalytic Activity of TiSiW_(12)O_(40)/TiO_2 in Synthesis of Butyric Esters

制备了新型固载杂多酸盐TiSiW12 O40 /TiO2 环境友好催化剂 ,并以丁酸丁酯的合成作为探针反应 ,系统考察了原料H4SiW12 O40 ·xH2 O与TiO2 摩尔比、焙烧温度、焙烧时间等制备条件对TiSiW12 O40 /TiO2 催化活性的影响 .实验表明 :制备催化剂的适宜条件为原料H4SiW12 O40 ·xH2 O与TiO2 摩尔比为 0 47,焙烧温度为 3 5 0℃ ,焙烧时间为 3 0h .利用该条件下制备的催化剂TiSiW12 O40 /TiO2 合成丁酸丁酯 ,正丁醇与正丁酸的投料摩尔比n(醇 )∶n(酸 ) =1 3∶1,催化剂的用量占反应物总投料质量的 1 3 % ,反应时间为 1h ,丁酸丁酯的产率为 97 2 % .该催化剂TiSiW12 O40 /TiO2 用于制备其它丁酸酯类 (如乙酯、丙酯、戊酯、异戊酯 )时同样取得了好的结果 .

A new environmentally friendly catalyst, TiSiW12 O-40/TiO2 was prepared. Its catalytic activity in esterification of n-butanoic acid and n-butyl alcohol was measured and compared with that of H3PW12O40 or H2SO4. TiSiW12O40/TiO2 showed better catalytic activity than H3PW12O40 or H2SO4. The optimum reaction condition was that the molar ratio of alcohol to acid was 1.3:1, the mass ratio of the catalyst used to the reactants was 1.3%, and the reaction time was I h. Under these conditions, the yield of ethyl ester is 87%, propyl ester 93%, n-butyl ester 97.2%, n-amyl ester 98%, and iso-amyl ester 95%, respectively.