Structure of copper sites in zeolites examined by Fourier and wavelet transform analysis of EXAFS
Vitaly L. Sushkevich, Оlga V. Safonova, Dennis Palagin, Mark A. Newton, Jeroen A. van Bokhoven
Abstract
-values and measured under cryogenic conditions, in combination with wavelet transform analysis enables the discrimination between the copper-oxo species having different structures. The zeolite topology strongly affects the copper speciation, ranging from monomeric copper species to copper-oxo clusters, hosted in zeolites of different topologies. In contrast, the variation of the Si/Al ratio or copper loading in mordenite does not lead to significant differences in XAS spectra, suggesting that a change, if any, in the structure of copper species in these materials is not distinguishable by EXAFS.
Topics & Concepts
CopperExtended X-ray absorption fine structureFourier transformWaveletFourier transform infrared spectroscopyFourier analysisWavelet transformSpectral lineMaterials scienceChemistryAbsorption spectroscopyPhysicsMathematicsMathematical analysisMetallurgyOpticsComputer scienceArtificial intelligenceAstronomyX-ray Spectroscopy and Fluorescence AnalysisX-ray Diffraction in CrystallographyElectron and X-Ray Spectroscopy Techniques