关键词: 沸石, 催化剂, 酯化, 活性

Abstract: The catalyst of solid superacid SO₄^2-/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 SO₄^2-/TiO₂ with the form of nanoparticles is supported on the surface of HZSM-5, the BET surface area of the catalyst is up to 309.2m²/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 pH for deposition is 8, impregnation concentration of H₂SO₄ is 0.5mol/L, impregnation time is 30min, calcination temperature and time are 550℃ and 4h, respectively. Under the optimal condition, solid superacid SO₄^2-/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 SO₄^2-/TiO₂-HZSM-5 catalyst is reused 6 times, the esterification rate of trimethylolpropane oleate decreases by 8.8%, i.e. the catalyst shows good reusability.

Key words: zeolite, catalyst, esterification, reactivity