CO2 adsorption in Y zeolite: a structural and dynamic view by a novel principal-component-analysis-assisted in situ single-crystal X-ray diffraction experiment

摘要: The increasing efficiency of detectors and brightness X-rays in both laboratory large-scale facilities allow the collection full single-crystal X-ray data sets within minutes. analysis these `crystallographic big data' requires new tools approaches. To answer needs, use principal component (PCA) is proposed to improve speed analysis. Potentialities limitations PCA were investigated using diffraction (XRD) collected situ on Y zeolite, which CO2, acting as an active species, thermally adsorbed while cooling from 300 200 K. For first time, thanks high sensitivity XRD, it was possible determine sites where CO2 adsorbed, increase their occupancy temperature decreased, correlated motion i.e. H2O Na+. allowed identification elimination problematic sets, better understanding trends occupancies Na+ water. quality for time calculation enthalpy (ΔH) entropy (ΔS) adsorption by applying van 't Hoff equation data. thermodynamic values carried out traditional PCA-based approaches, producing comparable results. obtained ΔH value significant involves systems (CO2 zeolite) with no toxicity, superb stability chemical inertness. Such features, coupled absence carbonate formation framework inertness upon adsorption, demonstrated bulk crystal experiment, suggest that phenomenon can be easily reversed a large number cycles, released demand. main advantages PCA-assisted reside its possibility being applied directly raw data, possibly `online' data-quality test during collection, without any priori knowledge structure.