THORONDOR: a software for fast treatment and analysis of low-energy XAS data

Abstract

THORONDOR is a data treatment software with a graphical user interface (GUI) accessible via the browser-based Jupyter notebook framework. It aims to provide an interactive and user-friendly tool for the analysis of NEXAFS spectra collected during in situ experiments. The program allows on-the-fly representation and quick correction of large datasets from single or multiple experiments. In particular, it provides the possibility to align in energy several spectral profiles on the basis of user-defined references. Various techniques to calculate background subtraction and signal normalization have been made available. In this context, an innovation of this GUI involves the usage of a slider-based approach that provides the ability to instantly manipulate and visualize processed data for the user. Finally, the program is characterized by an advanced fitting toolbox based on the lmfit package. It offers a large selection of fitting routines as well as different peak distributions and empirical ionization potential step edges, which can be used for the fit of the NEXAFS rising-edge peaks. Statistical parameters describing the goodness of a fit such as χ2 or the R-factor together with the parameter uncertainty distributions and the related correlations can be extracted for each chosen model.

Improving the Catalytic Performance of Cobalt for CO Preferential Oxidation by Stabilizing the Active Phase through Vanadium Promotion

“…After the reduction step in H 2 , the sample was cooled down to room temperature in He gas flow prior to the oxidation step in 10%O 2 /He. Data treatment, involving energy alignment, background subtraction using an asymmetric least squares fitting routine, and normalization to the total area under the curves, was performed by using the recently developed THORONDOR code …”

“…Data treatment, involving energy alignment, background subtraction using an asymmetric least squares fitting routine, and normalization to the total area under the curves, was performed by using the recently developed THORONDOR code. 57…”

Resonant soft X‐ray scattering in polymer science

“…Importantly, only an optical model of parallel aromatic groups reproduced experiment, while a herringbone orientation model failed. A second similar analysis on approximately 5 monolayers of a conjugated small molecule on an Au 111 substrate confirmed the flat‐lying molecules and compared DFT‐derived versus NEXAFS‐spectroscopy‐derived optical models 186 . In the future, it may be helpful to combine both ab‐initio (DFT) information with experimental measurements to generate the most accurate optical models.…”

“…These work very well for scattering data reduction and model fitting, but are generally not well equipped and optimized to deal with spectroscopy, and the process of processing each energy independently can be logistically difficult for large hyperspectral datasets. Similarly, while spectroscopy solutions 44,110,111 are excellent for analyzing and visualizing the spectroscopic axis of hyperspectral data, they are not well equipped and optimized to deal with scattering datasets and are usually designed to deal with only a handful of channels of data, not a 2D scattering image or 1D scattering profiles at each energy. This has meant that generally each RSoXS experiment is analyzed with custom software.…”

Effect of manganese promotion on the activity and selectivity of cobalt catalysts for CO preferential oxidation

“…NEXAFS data were acquired after 15 min at each selected temperature point. Data treatment, involving energy alignment, background subtraction using an asymmetric least square fitting routine and normalization to the total area under the curves, was performed by using the recently developed THORONDOR code [60]. The relative concentration of each oxidation state was calculated based on linear combination fit (LCF) analysis using as reference NEXAFS spectra of model Co and Mn oxides obtained from previous experiments [48] or from the literature [61].…”