The data is part of the PhD thesis defended at The University of Campinas (Universidade Estadual de Campinas, UNICAMP) by Leonardo da Silva Sousa on May 14th 2025 This dataset includes a combination of advanced spectroscopic and chemometric techniques to investigate the formation, agglomeration, and redispersion dynamics of supported metallic phases in heterogeneous catalysis, specifically targeting CO and CO2 conversion. Key techniques include in situ X-ray Absorption Fine Structure (XAFS), used to track changes in oxidation state and local coordination environment of active metal species under reaction conditions; Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), applied to monitor surface intermediates and adsorbates; and Modulation Excitation with Phase-Sensitive Detection (ME-PSD-DRIFTS), which enhances sensitivity and selectivity in detecting dynamic species. Additionally, Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) is employed to deconvolute overlapping spectral signals and extract chemically meaningful components. Together, these methods aim to provide a detailed, time-resolved understanding of catalyst structure–performance relationships and the dynamic behavior of metal-support interactions. Within the dataset there is a large scope of complementary characterization techniques, such as, in situ Diffuse Reflectance UV-Vis, CO-DRIFTS, X-ray Photoelectron Spectroscopy, Scanning Transmission Electron Microscopy, Thermogravimetric analysis, and X-ray Pair Distribution Function analysis.