Titanium Silicalite-1 Modified By Organic Base And Its Performance In Propylene Epoxidation

This paper used an unique Teflon lined autoclave. The unmodified TS-1 was located in the center of the autoclave and organic base solution was in the bottom. When heated, TS-1 catalyst was modified by the steam of organic base. As the autoclave cooled, TS-1 and organic base separated automatically.More importantly, the organic base could be reused. TS-1 catalysts were modified by several organic bases.The catalysts before and after treatment were characterized by XRD、FT-IR、UV-Vis、SEM and nitrogen physical adsorption.Catalytic performance of TS-1 modified were evaluated by the reaction of propylene epoxidation. The results were shown as follows:1. Compared with TS-1 unmodified, catalytic performance of TS-1 modified in propylene epoxidation were improved.Such as, XH2O2 increased significantly,but Spo reduced. Whereby, the EDA modified TS-1 had a higher catalytic activity.The XH2O2 and Spo were 95.5% and 82.3%, respectively.With the increasing EDA concentration, XH2O2 did not change significantly and Spo reduced at the same time.2. In the case of TS-1 modified by EDA, the influence of treatment time and temperature on the propylene epoxidation were investigated. The results showed that the proper condition was 48h and 170℃, respectively.3. This method of modification could be applied to variety of TS-1 so that the XH2O2 of TS-1 modified with this method were improved.4. The TS-1 extrudates before and after EDA treatment were evaluated by the reaction of propylene epoxidation in a fixed-bed reactor. When the n(C3H6)/n(H2O2) was reduced from 4.5 to 3.5, the modified TS-1 also showed a well catalytic activity. Compared with TS-1 unmodified, XH2O2 increased but Spo did not change significantly at the 40℃ condition.