二氧化钛负载磷钨钒杂多酸的制备及其催化氧化脱硫性能研究

A Study on Preparation and Oxidative Ddesulpurization Performance of Titanium Dioxide Supported Phosphotungste-Vanadium Heteropoly Acid

采用酸化-乙醚萃取法制备了Keggin结构的磷钨钒杂多酸,并分别采用浸渍法、溶胶-凝胶法制备了二氧化钛负载型杂多酸催化剂,采用紫外和红外光谱对催化剂进行表征。以H_(2)O_(2)为氧化剂,以二苯并噻吩(DBT)的正辛烷溶液为模型柴油,对其氧化脱硫反应进行了研究,考察了催化剂对模拟油品中二苯并噻吩(DBT)的氧化脱硫反应性能研究,考察了不同制备方法、不同负载量对催化剂脱硫效率的影响。结果表明,溶胶凝胶法制备的负载型催化剂明显优于浸渍法制备的催化剂,在反应温度50℃,反应时间为4小时,n(H_(2)O_(2))/n(s)=4∶1的优化条件下,DBT转化率达到89%。催化剂通过简单过滤法可分离回收,重复使用5次后DBT转化率为83%。

In this study,phosphotungsten-vanadium heteropoly acid with Keggin structure was synthesized by acidification-ether extraction method.TiO 2-supported heteropolyacid catalysts were then prepared using impregnation method and sol-gel method,respectively.The catalysts were characterized by UV and FT-IR spectra.Using H_(2)O_(2) as the oxidant and dibenzothiophene(DBT)as the model diesel oil,the oxidative desulfurization reaction was investigated.The effects of different preparation methods and capacities on the desulfurization efficiency of the catalyst were investigated.The results show that the catalyst prepared using sol-gel method performs better than the one prepared using impregnation method.Under the optimum conditions of reaction temperature being 50℃,reaction time being 4 h,n(H_(2)O_(2))/n(s)=4∶1,the DBT conversion rate reaches 89%.The catalyst can be separated and recovered by simple filtration,and the DBT conversion rate is 83%after reusing the catalyst for 5 times.