화학공학소재연구정보센터
Journal of Physical Chemistry B, Vol.108, No.26, 8970-8975, 2004
X-ray absorption fine structure analysis of the local environment of Fe in Fe/Al-MFI
An MFI zeolite framework containing iron and aluminum has been prepared and characterized by X-ray absorption spectroscopy. Extended X-ray absorption fine structure analysis indicates that in the as-prepared zeolite Fe is present in the framework but migrates to extraframework sites upon thermal activation at elevated temperature. In the absence of framework Al, Fe forms small particles of Fe3O4. When Al is included in the zeolite, extraframework Fe associates with framework Al in a manner identical to that observed in Fe-exchanged H-ZSM-5. Therefore, the presence of framework Al in the MFI structure plays a critical role in stabilizing atomically dispersed Fe.