In Situ X-ray Diffraction Study of Xe and CO2 Adsorption in Y Zeolite: Comparison between Rietveld and PCA-Based Analysis

Crystals

Luca Palin¹  Eleonora Conterosito¹  Mattia Lopresti¹ 

[1] Dipartimento di Scienze e Innovazione Tecnologica, Università degli Studi del Piemonte Orientale, viale T. Michel, 11-15121 Alessandria, Italy;

关键词: in situ X-ray powder diffraction;    Y zeolite;    Rietveld refinement;    principal-component analysis;    CO₂ sequestration;    Xe purification.;   

DOI  :  10.3390/cryst10060483

来源: DOAJ

【 摘 要 】

New very fast and efficient detectors, installed both on laboratory instruments and synchrotron facilities, allow the monitoring of solid-state reactions from subsecond to minute scales with the production of large amounts of data. Traditional “one-by-one” pattern refinement needs complementary approaches, useful to handle hundreds to thousands of X-ray patterns. Principal-component analysis (PCA) has been applied to these fields in the last few years to speed up analysis with the specific goals of assessing data quality, identifying patterns where a reaction occurs, and extracting the kinetics. PCA is applied to the adsorption/desorption of Xe and CO₂ within a Y zeolite. CO₂ sequestration is a key issue in relation to climate change, while Xe is a critical raw material, and its purification is an important topic for the industry. At first, results were compared to traditional sequential Rietveld refinement. CO₂-Y data were also compared with in situ single crystal data to investigate the different potentialities of PCA in the two cases. Two CO₂ adsorption sites were confirmed, while three Xe sites were identified. CO₂ showed a more linear adsorption trend with decreasing temperature, while Xe showed a more sigmoidal-like trend. Xe only showed site-dependent behavior in adsorption. Finally, PCA and correlation analysis, applied to analyze the parameters obtained from Rietveld refinement, highlighted finer details: in particular, this approach showed that the Y zeolite framework responded differently to CO₂ and Xe adsorption.

【 授权许可】

Unknown