硅铁ZSM-5催化剂上乙苯分子的吸附作用和表面反应

Adsorption and Surface Reaction of Ethylbenzene over Ferrosilicate with FeZSM-5 Structure

运用X光电子能谱、顺磁共振及穆斯堡尔谱研究了FeZSM-5沸石催化剂上乙苯的吸附及与催化剂的相互作用。沸石中骨架铁能与吸附的乙苯分子发生较强的相互作用。使Fe_2,电子结合能产生较大的低能位移;乙苯分子可以络合配位在沸石骨架中配位不饱和的Fe(Ⅲ)上,引起对应铁的顺磁信号和穆斯堡尔参数的变化,利用程序升温脱附和表面反应技术,通过考察吸附乙苯在FeZSM-5催化剂上的脱附和反应,进一步揭示了FeZSM-5乙苯脱氢催化活性中心的性质.

XPS, ESR and Mossbauer techniques were used to investigate the adsorption of ethylbenzene over FeZSM-5 zeolite catalyst. A stronger interaction between ethylbenzene and framework iron of FeZSM-5 is found, which results in a 0. 7 eV chemical shift of Fe2, binding energy towards a low value. Ethylbenzene molecule acting as a ligand could coordinate with the framework iron with coordination unsaturation to form a chemical bond. The study on the temperature programmed desorption and the surface reaction of ethylbenzene over FeZSM-5 further characterizes the catalytic active centers for ethylbenzene reactions.