原位红外光谱法研究Pd基贵金属催化剂上烯烃与芳烃加氢反应

In Situ FT-IR Study on Hydrogenation of Olefin and Aromatic on Pd-based Metal Catalysts

以环己烯、苯和苯乙烯为探针物,采用原位FT-IR技术对贵金属催化剂上(活性组分呈壳层分布)吸附烃类的原位加氢反应进行了研究。结果表明,催化剂对烯烃和芳烃中C=C键有活化作用,温度越高越有利于形成化学吸附;Pd基催化剂对烯烃有高的加氢活性,且双金属催化剂的活性明显优于单金属催化剂。双金属催化剂表面有吸附氢的存在,但吸附氢是有一定限度的。烯烃的C=C双键加氢和芳烃的苯环加氢在贵金属Pd基催化剂上发生在相同的活性中心上,存在有竞争吸附作用,彼此间有较强的相互影响。

Using cyclohexene, benzene and styrene as probe molecules, hydrogenate reaction in situ of hydrocarbons adsorbed on noble metal catalysts (egg-shell distribution) were researched by in situ FT-IR. The results showed that the C=C bond was active by catalysts and higher temperature was favor to chemical adsorption. The Pd-based catalysts had higher hydrogenated activity and the reactive activity of double-metal catalyst was super than that of single-metal catalysts. There was hydrogen adsorbed presented on the surface of the double-metal catalysts, but the adsorption amount of hydrogen was limited to a certain extend. The hydrogenation of C=C bond in olefin and benzene ring was occurred at the same active sites and there existed competitive adsorption result in mutual effect to each other.