sReactivation of CeO2-based Catalysts in the HCl Oxidation Reaction:In situ Quantification of the Degree of Chlorination and Kinetic Modeling - Research portal of Justus Liebig University Giessen:

Journal article

sReactivation of CeO2-based Catalysts in the HCl Oxidation Reaction:In situ Quantification of the Degree of Chlorination and Kinetic Modeling

Authors list: Sun, Y; Hess, F; Djerdj, I; Wang, Z; Weber, T; Guo, YL; Smarsly, BM; Over, H

Publication year: 2020

Pages: 5511-5522

Journal: ChemCatChem

Volume number: 12

Issue number: 21

ISSN: 1867-3880

Open access status: Hybrid

DOI Link: https://doi.org/10.1002/cctc.202000907

Publisher: Wiley

Abstract:
Deactivation of CeO2-based catalysts in the HCl oxidation reaction proceeds via selective bulk chlorination of the active CeO(2)component to form CeCl(3)xnH(2)O. We study the reactivation of two bulk-chlorinated CeO2-based Deacon catalysts by oxygen treatment at 430 degrees C, namely pure CeO(2)and 20 mol % of CeO(2)supported on preformed ZrO(2)particles (20CeO(2)@ZrO2), with a dedicated experiment. In the flow reactor setup we determinein-situthe degree of chlorination of the catalyst by quantifying down-stream with in-situ UV-Vis spectroscopy the total amount of chlorine in the catalyst that is exchanged by reoxidation at 430 degrees C. The activity of deactivated 20CeO(2)@ZrO(2)can be fully restored by oxygen exposure at 430 degrees C, while that of pure CeO(2)declines steadily. Since the UV-Vis analytics is fast and sensitive, we can follow the kinetics of reoxidation. To rationalize the observed kinetics, we develop a modified Johnson-Mehl-Avrami-Kolmogorov (JMAK) model based on a nucleation-and-growth approach for the reoxidation of the catalyst starting from the chlorinated phase. The fast reoxidation kinetics of chlorinated 20CeO(2)@ZrO(2)is traced to a fast nucleation rate.

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Citation Styles

Harvard Citation style: Sun, Y., Hess, F., Djerdj, I., Wang, Z., Weber, T., Guo, Y., et al. (2020) sReactivation of CeO2-based Catalysts in the HCl Oxidation Reaction:In situ Quantification of the Degree of Chlorination and Kinetic Modeling, ChemCatChem, 12(21), pp. 5511-5522. https://doi.org/10.1002/cctc.202000907

APA Citation style: Sun, Y., Hess, F., Djerdj, I., Wang, Z., Weber, T., Guo, Y., Smarsly, B., & Over, H. (2020). sReactivation of CeO2-based Catalysts in the HCl Oxidation Reaction:In situ Quantification of the Degree of Chlorination and Kinetic Modeling. ChemCatChem. 12(21), 5511-5522. https://doi.org/10.1002/cctc.202000907