SO_4^(2-)/TiO_2-HZSM-5固体超强酸催化剂的制备及酯化性能  

Preparation of solid superacid SO_4^(2-)/TiO_2-HZSM-5 catalyst and its catalytic performance in esterification

作　　者：李三喜[1] 徐妍如 王松[1] 

机构地区：[1]沈阳工业大学理学院,辽宁沈阳110870

出　　处：《化工进展》2015年第3期745-750,共6页Chemical Industry and Engineering Progress

基　　金：辽宁省沈阳市科技专项资金项目(沈科发[2012]29号)

摘　　要：采用溶胶-凝胶法制备了HZSM-5分子筛负载SO42-/TiO2固体超强酸催化剂,利用直接酯化法催化合成三羟甲基丙烷油酸酯。通过IR、XRD、BET、SEM对催化剂进行了表征,结果表明TiO2以纳米颗粒的形式附着于HZSM-5分子筛表面,且负载后催化剂的比表面积高达309.2m2/g,比HZSM-5分子筛提高了45.6m2/g,且催化剂具有强酸性(-13.8<H0<-12.14)。探讨了沉淀pH值、焙烧温度、焙烧时间等催化剂制备条件对SO42-/TiO2-HZSM-5固体超强酸催化剂催化三羟甲基丙烷油酸酯酯化反应活性的影响。结果表明在沉淀pH=8、硫酸的浸渍浓度为0.5mol/L、浸渍时间为30min、焙烧温度为550℃、焙烧时间4h的条件下,SO42-/TiO2-HZSM-5固体超强酸催化剂催化活性最高,三羟甲基丙烷油酸酯的酯化率高达97.6%;抗乳化性能良好,油水分离时间为5min。SO42-/TiO2-HZSM-5固体超强酸催化剂在重复使用6次的情况下,酯化率下降8.8%,催化剂的重复使用性能良好。The catalyst of solid superacid SO42-/TiO2 supported on HZSM-5 was prepared by sol-gel process. The trimethylolpropane oleate was synthesized by direct esterification. The catalyst was characterized by IR, XRD, BET, and SEM. The results show that SO42-/TiO2 with the form of nanoparticles is supported on the surface of HZSM-5, the BET surface area of the catalyst is up to309.2m2/g,increasing 45.6m2/g compared with HZSM-5,and the catalyst is with better solid acidity.The effects of catalyst preparation conditions on catalytic reactivity were studied. The optimal condition for the preparation of the catalyst was obtained as follows ： the p H for deposition is 8, impregnation concentration of H2SO4 is 0.5mol/L,impregnation time is 30 min,calcination temperature and time are550℃ and 4h,respectively. Under the optimal condition,solid superacid SO42-/TiO2-HZSM-5 catalyst has the best the catalytic performance,the esterification rate of trimethylolpropane oleate is as high as 97.6%,the product can exhibit excellent emulsification resistive property,and oil-water separation time is 5min.After solid superacid SO42-/Ti O2-HZSM-5 catalyst is reused 6 times, the esterification rate of trimethylolpropane oleate decreases by 8.8%,i.e. the catalyst shows good reusability.

关 键 词：沸石 催化剂 酯化 活性 

分 类 号：TS195.2[轻工技术与工程—纺织化学与染整工程]