Identifying Cu-oxo species in Cu-zeolites by XAS: a theoretical survey by DFT-assisted XANES simulation and EXAFS wavelet transform

We present a combined DFT-assisted analysis based on both full-potential XANES simulation and Wavelet Transform Analysis (WTA) applied to computed EXAFS signals. The resulting theoretical insights set the bases for an easier and more robust interpretation of the XAS data collected on Cu-zeolite systems. In particular, we evidenced possible fingerprint features in the XANES region, together with the difficulties in discriminating among monomeric and dimeric CuII moieties solely based on their XANES signatures. We then show the potential of Wavelet Transform Analysis as a new tool in the identification and visualization of EXAFS atomic contributions, to possibly enhance the EXAFS sensitivity to the nuclearity of Cu-oxo species in Cu-zeolites.Graphical abstract
Source: Catalysis Today - Category: Chemistry Source Type: research
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