Data set from: In situ and operando laboratory X-ray absorption spectroscopy at high temperature and controlled gas atmosphere with a plug-flow fixed-bed cell

This dataset contains raw (µ(E)Q) and normalized X-ray absorption spectroscopy (XAS) data supporting the study “In situ and operando laboratory X-ray absorption spectroscopy at high temperature and controlled gas atmosphere with a plug-flow fixed-bed cell.” It includes in situ oxidation of 5% Ni/MnO (Mn K-edge) and both operando and in situ investigations of 20-NiO/COK-12 under CO₂ methanation conditions. Each dataset folder provides raw spectra and normalized data processed using the ATHENA module of the Demeter software package. Measurement times and dwell conditions (e.g., H2CO2_400C_20min) are noted in the file headers.These data demonstrate laboratory-based operando XAS capabilities for catalyst studies under realistic reaction environments.