【摘要】 通过溶胶凝胶-常压干燥法制备不同干燥温度的Si O2-Ti O2复合气凝胶,将其用作以N,N-二甲基甲酰胺(DMF)为溶剂,H2O2[n(H2O2)=30%]为氧化剂的苯乙烯环氧化催化剂,结合XRD、UV-vis、FT-IR等表征手段研究了干燥温度对其催化性能的影响。同时考察了双氧水用量、反应温度、反应时间、催化剂用量等反应条件对反应性能的影响。结果表明,干燥温度提高,催化剂性能降低,最佳干燥温度为120℃。最佳反应条件为:n(H2O2)/n(苯乙烯)=0.5,反应温度为60℃,反应时间为6 h,催化剂质量为0.25 g。更多还原

【Abstract】 Si O2-Ti O2 composite aerogels dried under different temperature are prepared by sol-gel and atmosphereic pressure drying method,and characterized by XRD,UV-vis spectroscopy and FT-IR analysis. The effect of drying temperature on the catalytic performances of Si O2-Ti O2 composite aerogels is investigated for the styrene epoxidation using DMF as the solvent and aqueous H2O2 as the oxidant. The influences of reaction conditions,including n( H2O2/styrene),reaction time,reaction temperature,amount of catalyst and catalyst reusability,are also performed. The results show that the performance of catalyst is decreased with increasing drying temperature. The optimal drying temperature is120℃. The optimal reaction conditions are: 0. 5 of n( H2O2/ styrene),6 hours of reaction time,60℃ of reaction temperature,0. 25 g of catalyst.更多还原