硅胶固载钛酸酯的制备及其对酯化反应的催化研究

以四氯化钛和不同物质的量比的2-乙基己醇反应,然后与硅胶作用制备了硅胶固载化催化剂.合成条件用正交试验进行了优化.结果表明:最适宜反应条件为钛醇物质的量比为1∶3;反应温度120℃;反应时间2h;理论固载量为20%.测定了固载钛酸酯的钛含量,并用IR对固载催化剂进行了初步表征.以不同物质的量比固载催化剂进行了苯甲酸和2-乙基己醇酯化反应的催化研究,同时与未固载钛酸酯进行了对比,发现固载催化剂活性明显降低,其中以钛与醇物质的量比1∶2制得的固载催化剂效果较好.经5次催化剂重复使用试验,表明硅胶固载催化剂具有很好的稳定性,重复使用性能良好.

Study on titanates Catalysts Supported on Silica Gel and Application to esterification Reaction

The solid supporting catalysts——silica supporting titanates are synthesized by the reactions of titanium tetrachloride firstly with 2-ethylhexanol of different mole ratios and then with silica gel.The reaction conditions are optimized by orthogonal experiments.The results show that the prefer conditions are the titanium tetrachloride to 2-ethylhexanol mole ratio of 1∶3;the reaction temperature of 120 ℃;the reaction time of 2 h and the theoretic solid supporting rate of 20%.The content of titanium in the solid supporting titanate is measured,and the silica supporting catalysts are characterized by IR spectroscopy.The solid supporting catalysts of different amount are applied to the esterification reaction of bezoic acid with 2-ethylhexanol,and the catalysis effect of them is compared with that of titanate.It is found that the the activity of solid supporting catalysts is worse than that of titanate,but among the solid supporting catalysts,the solid supporting catalyst prepared by the titanium tetrachloride to 2-ethylhexanol mole ratio of 1∶2 has the best catalyzing effect,and it has also higher activity after being used repeatedly 5 times,which shows the silica supporting catalyst has good stability.