稀土改性固体超强酸SO_4^(2-)/TiO_2-La_2O_3催化合成丙酸系列酯

Synthesis of Propionates by Using SO_4^(2-)/TiO_2-La_2 O_3 as Catalyst

报道了以稀土改性固体超强酸SO42 /TiO2 La2 O3 为多相催化剂 ,通过乙醇、正丙醇、正丁醇、异丁醇、正戊醇、异戊醇分别和丙酸反应合成了丙酸系列酯 ,探讨了该催化剂SO42 /TiO2 La2 O3 对酯化反应的催化活性 ,较系统地研究了醇酸摩尔比 ,催化剂用量 ,反应时间诸因素对产率的影响。实验表明 :合成丙酸系列酯的优化条件为n(醇 ) /n(丙酸 ) =1 .2 / 1 ,催化剂用量为反应物料总量的 2 .5 % ,反应时间为 1 .5h。上述优化条件下 ,丙酸乙酯的产率为 2 0 .9% ,丙酸丙酯的产率为 64.9% ,丙酸丁酯的产率为 83 .6% ,丙酸异丁酯的产率为 69.7% ,丙酸戊酯的产率为 87.5 % ,丙酸异戊酯的产率为 83 .3 %。

SO 4 2- /TiO 2 -La 2 O 3 were used as catalyst for the esterification of propionic acid with ethanol, propanol, n-butanol, iso-butanol, n-amyl alcohol and iso-amyl alcohol. Effects of catalyst dosage, reaction time, molar ratio of reactants and amount of an agent which taking off water on synthesizing propionates were investigated. A suitable condition for synthesizing propionates was obtained, that is, molar ratio of alcohol to propionic acid is 1.2:1, the mass ratio of catalyst used to the reactants 2.5 %, the reaction time 1.5 h. Under this condition, yield of ethyl propionate is 20.9%, n-propyl propionate is 64.9%, n-butyl propionate is 83.6%, iso-butyl propionate is 69.7%, n-amyl propionate is 87.5% and iso-amyl propionate is 83.3%.