Influence of the Experimental Setup on X-ray Diffraction Data of Zeolite ZSM-5
Zeolite ZSM-5 is regularly used as catalyst for hydrocarbon cracking and fluid catalytic cracking in the petrochemical industry. Due to their complex framework structures, characterization of zeolites via X-ray diffraction places high demands on the used diffractometer.
Zeolites are aluminosilicates with a microporous structure, providing the possibility to adsorb small molecules within their pores. Adsorbed water molecules, and their release in the form of steam upon heating, resulted in the name zeolite in the 18th century.1 Since the adsorption is selective with respect to the size and structure of the adsorbed molecules, zeolites are promising candidates for many catalytic applications. Many different zeolites have been investigated and are also industrially produced for use in different catalytic applications.
ZSM-5 is the zeolite with the largest industrial production worldwide.2 The specific microporous structure of ZSM-5 makes it a very effective catalyst for hydro-carbon cracking and especially for fluid catalytic cracking (FCC) in the petrochemical industry. ZSM-5 has been synthesized and investigated since the 1970s3,4 and from the very beginning X-ray diffraction (XRD) has been an important characterization technique to study its atomic structure. However, even today, the sharp diffraction peaks at small diffraction angles, caused by the low-defect structure with large crystallographic unit cells, regularly present an experimental challenge. Difficulties with strong peak asymmetry or peak overlap can only be avoided by using a diffractometer with high resolution, low angular divergence and low background even at very small diffraction angles.
In this study, a ZSM-5 powder sample is investigated with XRD using the Automated Multipurpose Powder X‑Ray Diffractometer XRDynamic 500 from Anton Paar.
1. A.F. Cronstedt, Kongl. Vetenskaps Academiens Handlingar Stockholm 17 (1756), 120
2. B. Yilmaz, U. Müller, Top. Catal. 52 (2009), 888-895
3. R.J. Argauer, G.R. Landolt, US patent 3,702,886 (1972)
4. G.T. Kokotailo, S.L. Lawton, D.H. Olson, W.M. Meier, Nature 272 (1978), 437-438
Get the document
To receive this document please enter your email below.