氧化铁系催化剂上乙苯脱氢反应机理研究(Ⅰ)——乙苯吸附态的“原位”红外光谱及脱氢反应的动力学同位素效应  

Study of Reaction Mechanism for Dehydrogenation of Ethylbenzene Over Iron-Oxide Catalysts(Ⅰ)-In-situ FT-IR spectra of Ethylbenzene Adspecies and Kinetic isotope Effects of the Dehydrogenation Reaction

作　　者：陈建平 何淡云[1] 曹守镜[1] Chen Jianping;He Danyun;Cao Shoujin(Dept of Chem,Xiamen Univ.,Xiamen)

机构地区：[1]厦门大学化学系

出　　处：《高等学校化学学报》1986年第11期1020-1025,共6页Chemical Journal of Chinese Universities

摘　　要：本文用“原位”FT-IR光谱研究乙苯在氧化铁系催化剂上的吸附物种,结合动力学同位素效应对反应速率控制步骤的考察,讨论了该反应的微观机理。The IRspectra of adspecies of ethylbenzene and ethylbenzene-d10 were observed at the room temp and reaction temp,respectively.The relative rates of dehydrogenation of several kinds of deuterium labelled ethylbenzene have been determined under the same reaction conditions.Apossible mechanistic pathway for the dehydrogenation of ethylbenzene may then be proposed as following.First,the ethylbenzene molecule is adsorbed on the iron oxide catalyst surface,the α-His abstracted by lattice oxygen of the catalyst to form a surface-OH,and a pseudo π-allyl intermediate of the ethylbenzene residual,which may be coverted to a pseudo σ-allyl intermediate The β-Hmay then be ruptured to form styrene molecule and a Fe-Hbond on a neighbouring Fe^(+2(+3))in the rate determining step.

关 键 词：速率控制步骤 脱氢反应 乙苯 氧化铁系催化剂 动力学同位素效应 红外光谱 吸附态 微观机理 

分 类 号：TQ2[化学工程—有机化工]