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RESEARCH PRODUCT
Analysis of Active-Site Distribution in ZSM-5 Crystals by Infrared Microscopy
Ferdi SchüthFerdi SchüthR. Althoffsubject
ChemistryResolution (electron density)MicroscopyAnalytical chemistryInfrared spectroscopyElectron microprobePhysical and Theoretical ChemistryFourier transform infrared spectroscopyZSM-5Infrared microscopySingle crystalCatalysisdescription
Abstract The acid Site distribution over large ZSM-5 crystals was analyzed using FTIR microscopy. Results of the analysis of the OH-stretching vibrations and of vibrations of pyridine adsorbed on Bronsted and Lewis acid sites were found to be in good agreement. The resolution which can be obtained using this novel technique is about 10-20 μm. This limits the application to large crystals as analyzed in this study. Comparison of the results of IR microscopy with aluminum distributions obtained by electron microprobe analysis revealed that IR microscopy cannot resolve inhomogeneities on a scale smaller than the above-stated limits. The results of both methods on a larger scale, however. are in very good agreement. Using a combination of both techniques, it is possible to obtain a clearer picture of the distribution of acid sites in large zeolite crystals, where electron microprobing gives the higher resolution, and IR microscopy allows the determination of the types of aluminum site present in the zeolite spatially resolved.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1993-10-01 | Journal of Catalysis |