CoMo/Al2O3催化剂上FCC汽油加氢脱硫活性研究

Research of hydrodesulfurization activity of FCC gasoline on CoMo/Al_2O_3 catalysts

采用等体积浸渍法合成了Co/Mo/Al_2O_3催化剂,采用N_2吸附-脱附、扫描电镜(SEM)对催化剂进行了表征,针对CoMo/Al_2O_3催化剂,改变温度和空速进行催化裂化(FCC)汽油加氢脱硫评价试验,考察了FCC汽油中单环噻吩类和苯并噻吩类硫化物的脱硫率,发现了加氢脱硫活性与硫化物的电子云密度相关联的规律:硫化物的电子云密度越高,则加氢脱硫转化率越高,硫化物越容易脱除。采用Gaussian 03程序中的密度泛函理论(DFT)方法,在B3LYP/6-31G水平上对噻吩及其衍生物的分子结构进行了全优化计算,获得了噻吩及其衍生物中双键键级及硫原子的电负性,验证了试验中硫化物加氢脱硫和其电子云密度相关联的规律。

Co/Mo/Al2O3 catalyst was prepared by impregnation method and characterized by N2 adsorption-desorption and scanning electron microscope （SEM）. The hydrodesulfurization conversion of the monoeyclic thiophene and benzothiophene on Co/Mo/Al2O3 catalysts was investigated at different temperature and space velocity. The rule of the hydrodesulfurization on the Co/Mo catalyst was found as follows： The hydrodesulfurization activity of sulfide compounds was related to their electron cloud density, the higher electron cloud density of the reactant molecules were, the higher the conversion of the hydrodesulfurization was. The molecular structure of thi- ophenic compounds were studied by density functional theory （DFT） at the B3LYP/6-31G level to obtain the corresponding atom charges and the order of double bond. The result was consistent with the previous experiment.