VxTi复合氧化物催化剂用于二氧化碳气氛乙苯脱氢的研究

采用溶胶-凝胶法制备了以TiO₂为基体的VxTi复合氧化物催化剂，该催化剂用于乙苯二氧化碳低温氧化脱氢制苯乙烯反应。考察了活性组分含量和焙烧温度对催化剂活性的影响。结果表明，活性金属钒的添加有助于提高脱氢反应性能，但存在一适量值，摩尔分数超过5%，催化脱氢活性下降。通过XRD分析发现，不同焙烧温度制备的VxTi催化剂中TiO₂的晶相不同，随着温度的升高，TiO₂的晶相将由锐钛矿型转变为金红石晶相。TiO₂锐钛矿型晶相有利于苯乙烯选择性的提高，而金红石晶相则不利于催化剂的脱氢反应。

Ethylbenzene dehydrogenation with CO 2 catalyzed by V xTi mixed oxides catalysts

V_xTi mixed oxides catalysts were prepared by sol-gel method,using TiO_2 as the substrate,and used as the catalysts for ethylbenzene dehydrogenation in the presence of carbon dioxide at lower reaction temperature.Influences of active component content and calcinations temperature were investigated.The results indicated that the addition of vanadium enhanced the dehydrogenation activity,but the activity declined when content of vanadium exceeded 5%.XRD results showed that V_xTi catalysts prepared at different temperature had different crystalline phase;TiO_2 phase transferred from anatase to rutile with increase in calcination temperature.The anatase phase of TiO_2 in V_xTi catalyst favored selectivity to styrene,while rutile phase of TiO_2 inhibited ethylbenzene dehydrogenation(activity.)