【摘要】 沉淀法制备的Ru-Zn体系用于苯选择加氢制环己烯,苯转化40%时,环己烯选择性达85 5%。XRD研究证实了Zn和Ru以固溶体形式存在。用噻吩吸附发现,10-6数量级的硫对选择性产生明显影响。XRD半高宽法测得Ru微晶粒径3～5nm。Ru-Zn催化剂BET比表面积62 5m2/g,平均孔径16 05nm,具有两端开放的管状毛细孔结构,反应可利用的孔分布均匀。并与浸渍法制备的Ru-Zn/SiO2对比,探讨催化剂的活性相,活性中心性质,及比表面积、孔性质与活性选择性的关系。更多还原

【Abstract】 Selective hydrogenation of benzene was conducted over Ru-Zn catalysts prepared by precipitation method,the selectivity to cyclohexene reached 85 5% at a benzene conversion of 40%.Characterization of the catalysts was carried out with XRD,adsorption of thiophene,BET surface area and pore distribution measurement.Only peaks corresponding to Ru were determined in XRD patterns,indicating the existence of Ru and Zn as a solid solution with Zn atoms dispersed incidentally and disorderly in Ru crystal lattices.Thiophene adsorption test,revealed that the selectivity was apparently influenced by sulphur of an amount of the order 10 -6 .Ru-Zn crystallite sizes obtained from XRD were in the range of 3～5 nm.BET surface area of the catalysts was around 62 5 m 2/g,and the average pore diameter of which was 16 05 nm.Pore structure of the catalysts was of open capillary columns,with homogeneous distribution of the utilizable pores.The active phase and nature of active center of Ru-Zn were studied by comparison with Ru-Zn/SiO 2 prepared by the impregnation method.The relationship between surface area,pore nature and activity as well as selectivity was also discussed.更多还原