کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
42239 | 45916 | 2010 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Estimation of the fractions of different nuclear iron species in uniformly metal-exchanged Fe-ZSM-5 samples based on a Poisson distribution Estimation of the fractions of different nuclear iron species in uniformly metal-exchanged Fe-ZSM-5 samples based on a Poisson distribution](/preview/png/42239.png)
A simple calculation method is presented which allows for estimation of the fractions of different iron species in Fe-ZSM-5 based on statistical considerations. Under the assumption of uniformly distributed iron, the probability with which Fe–O–Fe bridged and higher nuclear Fe-species are formed in a Fe-ZSM-5 sample may be calculated based on a simple Poisson distribution. The results of these calculations were compared with DR-UV/vis and DRIFT spectroscopy measurements on a variety of Fe-ZSM-5 samples with different Fe/Al ratios. Moreover, the calculated concentration profiles were checked with literature data from other studies. It is shown that the fractions of different iron species in Fe-ZSM-5 can be estimated by this calculation method with satisfactory accuracy, provided that the metal-exchange process resulted in a uniform distribution of iron in the zeolite. The method may be useful for verifying of analytical results, understanding of observed activity patterns and may facilitate the identification of activity–structure relationships.
A simple calculation method is presented which allows for estimation of the fractions of different iron species in Fe-ZSM-5 based on statistical considerations. The results of these calculations were compared with DR-UV/vis and DRIFT spectroscopy measurements on a variety of Fe-ZSM-5 samples with different Fe/Al ratios.Figure optionsDownload high-quality image (55 K)Download as PowerPoint slide
Journal: Applied Catalysis A: General - Volume 373, Issues 1–2, 31 January 2010, Pages 168–175