Ru/AC催化剂上不同取代苯液相加氢活性的比较研究

采用自制的Ru/AC催化剂,以异丙苯作反应物系统考察了反应条件:时间、温度、氢压、催化剂用量、底物浓度等对苯环加氢反应的影响,并与不同供电子与吸电子基团的取代苯加氢反应活性进行了比较.用XRD和XPS对催化剂进行了表征.结果表明:相同的实验条件下,带供电子基团的取代苯的加氢活性高于带吸电子基团取代苯.带供电子基团取代苯的加氢活性顺序如下:叔丁基苯>异丙苯>乙苯>甲苯>苯,间二甲苯>对二甲苯>邻二甲苯.带吸电子基团取代苯的加氢活性顺序为:苯酚>对氯苯胺>氯苯>硝基苯.该催化剂呈微晶状态,粒度很小,经氢气还原后表面上钌主要为Ru0,它们对供电子基团取代苯有很高的芳环加氢活性.

Comparison of Catalytic Activity for Hydrogenation of Different Subsititution Benzene over Ru/AC

Ru/AC catalyst was prepared by impregnation method.The effect of reaction time,temperature,hydrogen pressure,amount of catalyst and concentration of substrate on hydrogen-ation of isopropyl-benzene have been investigated.The differences of reactivity between isopropylbenzene and other substituted benzene with different electron acceptor and donor have been compared.The hydrogenation reactivity of the substituted benzene with electron donor was higher than that with electron acceptor,The sequence of hydrogenation conversion for the substituted benzene with electron donor was: tert-butylbenzene >isopropylbenzene>ethylbenzene>toluene>benzene.The catalyst was characterized by XRD and XPS.The results showed that the metal particle size on the supported catalyst is very small micro-crystal,Ruthinum on the surface of support is Ru~(0 ),when the catalyst was reduced by hydrogen.Its catalytic reactivity for the hydrogenation of substituted benzene with electron donor group is very high.