对甲苯磺酸改性SBA-15的合成及催化合成乙酸正丁酯

Synthesis and catalytic activity of TsOH-modified SBA-15 mesoporous molecular sieve

采用浸渍法将含有磺酸基的对甲苯磺酸负载在SBA-15表面上,合成含有一定酸性的固体酸催化剂TsOH-SBA-15。催化剂的制备条件为:对甲苯磺酸的浸渍浓度为0.5 mol/L,焙烧温度为300℃,焙烧时间为4 h。用XRD,IR,DTA/TGA,氮吸附-脱附等方法对改性后的样品进行表征。结果表明,改性后的SBA-15分子筛的结构未发生变化,仍具有有序孔道结构。TsOH-SBA-15催化剂对冰乙酸和正丁醇的酯化反应具有较高的活性,正交实验结果为:反应时间80 m in,n(冰乙酸)∶n(正丁醇)=1∶1.2,催化剂用量为冰乙酸质量的5%,此时酯化率可达到95%。

The SBA-15 mesoporous silica materials containing alkyl sulfonic acid group was prepared by impregnating TsOH to the surface of SBA-15. The catalyst prepared by impregnating SBA-15 in solution of 0.5 mol/L TsOH and being calcined at 300 ℃ for 4 h acetate. The samples were characterized by XRD, IR, DTA/TGA, N2 adsorption-desorption techniques. The TsOH-SBA-15 keeps the highly ordered meso- porous structure and does not change the mesoporous channel structure of SBA-15 molecular sieve. TsOH- SBA-15 was an excellent catalyst to synthesis of n-butyl acetate. The optimum conditions of the esterification by orthogonal experiments were studied： The mole ratio of acetic acid to n-butanol 1 ： 1.2 , the amount of catalyst 5% ,reaction time 80 min. The yield of n-butyl acetate could reach 95%.