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采用TPR,H_2化学吸附,TPD,TEM和DRS等方法对一组组成相同制法不同的Pt-Re/Al_2O_3催化剂进行了表征。TPR,H_2化学吸附等结果表明,Pt-Re/Al_2O_3催化剂中Re是通过与Pt的相互作用形成有高温吸附H_2中心及抗积炭能力的Pt-Re集团,从而提高了重整催化剂的活性和稳定性。制备方法的不同对催化剂活性表面的形成及铂铼相互作用有重要影响。以羰基金属原子簇化合物制备的Pt_5Re_2催化剂的Pt和Re的相互作用程度最大,这种相互作用从TPR和DRS测定中得到验证。电镜观察发现Pt_5Re_2催化剂表面的金属晶粒分布比常规Pt-Re小且均匀。由于担载羰基化合物在脱羰过程中CO发生歧化生成的微量碳物类使Pt_5Re_2具有较好的活性、芳构化选择性和稳定性。
A series of Pt-Re / Al 2 O 3 catalysts with the same preparation method were characterized by TPR, H 2 chemisorption, TPD, TEM and DRS methods. The results of TPR, H 2 chemisorption and so on show that Re in Pt-Re / Al 2 O 3 catalyst can form Pt-Re group with high temperature to adsorb H 2 center and resistance to carbon deposition through the interaction with Pt, thus improving the activity of reforming catalyst and stability. The different preparation methods have an important influence on the formation of the active surface of the catalyst and the interaction of platinum and rhenium. Pt_5Re_2 catalyst prepared from carbonyl metal cluster compounds has the highest interaction between Pt and Re, and this interaction is verified by TPR and DRS measurements. Electron microscopy showed that the distribution of the metal grains on the Pt 5 Re 2 catalyst surface is smaller and more uniform than that of the conventional Pt-Re. As the supported carbonyl compounds in the decarbonylation CO disproportionation generated trace carbon species to Pt_5Re_2 has better activity, aromatization selectivity and stability.