The Optimization Of Styrene Epoxidation With H₂O₂ On TS-1

Styrene epoxide is a kind of fine chemical material and is used as thinner of epoxide resin, uv-absorbent, spicery and steady material. And it is a very important chemical middle material in the fields of organic reaction, medicine industry, spicery industry and so on. Styrene epoxide is produced by halogenate-alcohol method with styrene in industry, but the halogenate-alcohol consumes a mass of substances and energy, and pollution is seriesly graveness. So the method is must improved. But a method of epoxidation is environal friendly green process with H2O2 on titanium silicon molecular sieve.The article is the optimization of epoxidation system reaction. First of all,it studied influences of different additives and the presence of water on the epoxidation of styrene. It was found that the additive could significantly increase the selectivity of styrene oxide, while there is a great influence to the selectivity of the target product duing to the water'acid.TS-1 zeolite samples with different crystal sizes(1,4 and 7μm) and different si/ti molar ratio(33,50,100 and 200) were synthesized hydrothermally. And TS-1 with 100 nm was modified by propylamine treatment. The samples were characterized by SEM,XRD,UV-Vis, IR, UV-Raman and the catalytic performance of TS-1 zeolite was studied in styrene oxidation to styrene epoxide. The results showed that the size of crytal and si/ti molar ratio had little influence on the selectivity of styrene oxidation to styrene epoxide, but as the increasing of crytal size and si/ti molar ratio, the conversion of styrene is gradually decreased.The catalysis was modified by different methods.The activity and selectivity to styrene epoxide with H2O2 on TS-1 was increased by the characterization of TS-1 modified by organic bases treatment.Under reaction conditions:50 mmol styrene, acetone 15ml, urea/H2O2 mole ratio of 2:1, mole ratio of styrene to hydrogen peroxide 3,0.2g TS-1 modified by hydrothermal treatment and organic bases treatment, reaction temperature 65℃and reaction time 10h, the conversion of styrene was 27.92%, the selectivity of styrene epoxide was 82.04%, the utility of hydrogen peroxide was 94.98%.