Pr-rich cerium-zirconium-praseodymium mixed oxides for automotive exhaust emission control
Résumé
This study describes the textural, structural, redox properties, oxygen reactivity of two Pr-rich cerium-zirconium-praseodymium (CZP) oxides (Ce 0.45 Zr 0.10 Pr 0.45 O 2-x and Ce 0.475 Zr 0.05 Pr 0.475 O 2-x) and their catalytic activity for propane and CO oxidation in both stoichiometric and lean conditions, two important reactions for automotive exhaust emission control. The concentration of oxygen vacancies can be tuned by the quantity of Pr 3+ cations which depend both on the preparation method and the composition. The Pr 4+ (4f 1)/Pr 3+ (4f 2) ratio was accurately determined by magnetic measurement. A highly energetic grinding step was found to double this Pr 3+ concentration, resulting in a strong enhancement of the lowtemperature reducibility, bulk oxygen mobility and catalytic activity for propane deep oxidation. Pr-rich CZP oxides seem to be less relevant for CO oxidation, which is mainly driven by the specific surface areas. These Pr-rich CZP mixed oxides present better performances for lean conditions, suggesting their possible role in diesel oxidation catalysts applications.
Domaines
Catalyse
Fichier principal
Fahed et al Applied Catalysis A 2022 Authors version.pdf (1.41 Mo)
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