摘要
采用气相流动吸附法制TiO_2/SiO_2复合载体,浸渍法担载一定量MoO_3。用XRD、LRS和TPR等技术考察了MoO_3在TiO_2/SiO_2表面的分散状态,中压固定床反应装置测定MoO_3/TiO_2—SiO_2、MoO_3/SiO_2催化剂的噻吩加氢脱硫、环己烯加氢和苯加氢活性。结果表明:(1)TiO_2的加入有利于加强MoO_3与SiO_2之间的相互作用,促进MoO_3在载体表面的分散,提高其分散阈值:(2)当MoO_3载量低于分散阈值时,其HDS、HYD和BHD活性随MoO_3载量的增加而明显增大,但在高于分散阈值后,几乎保持不变,能明显体现负载型Mo催化剂在HDS、HYD和BHD反应中的阈值效应;(3)MoO_3/TiO_2—SiO_2催化剂的HDS、HYD和BHD活性都较MoO_3/SiO_2催化剂高,TiO_2能很大程度地改善MoO_3/SiO_2催化剂的HDS、HYD活性。
TiO2/SiO2 complex supporsys prepared by using gas phase adsorption method and a definite amount of MoO3 is deposited on TiO2/SiO2 by means of impregnation. Such techniques as XRD,LRS,TPR,etc. are used to study the surface dispersion state of MoO3 on the surface of TiO2/SiO2.thiophene hydrodesulfurization(HDS),cyclohexene hydrogenation(HYD)and benzene hydro-genation(BHD)activities of MoO3/TiO2 -SiO2,MoO3/SiOz catalysts are measured in a fixed-bed reactor. The results are as follows ; (l)The incorporation of TiO2 can enhanced interaction between MoO3 and SiO2 support,promoted the dispersion of MoO3 on complex support,raised the dispersion threshold of MoO3. (2)It is observed that HDS.HYD and BHD activities greatly increased with MoO3 content up to dispersion threshold and then remained almost constant independent of the MoOs content. It could embody objectively the effect of threshold value of supported-Mo catalysts in the HDS.HYD and BHD reaction. (3)The HDS.HYD,BHD activities of MoO3/TiO2-SiO2 catalyst are higher than that of MoO3/SiO2 catalyst,TiO2 can greatly improve the HDS.HYD activities of MoO3/ SiO2 catalyst.
出处
《嘉应大学学报》
2001年第3期23-27,共5页
Journal of Jiaying University
基金
福建省自然科学基金(B93012)
