【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。更多还原

【Abstract】 The IR spectra 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.A possible 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-H is 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-H may then be ruptured to form styrene molecule and a Fe-H bond on a neighbouring Fe+2(+3)in the rate determining step.The IR spectra 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.A possible 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-H is 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-H may then be ruptured to form styrene molecule and a Fe-H bond on a neighbouring Fe+2(+3)in the rate determining step.更多还原