Effect of Ce Substituted Hydrotalcite-derived Mixed Oxides on Total Catalytic Oxidation of Air Pollutant
Résumé
Co6Al2-yCeyHT hydrotalcite like compounds were synthesized by co-precipitation method. Hydrotalcite structure as well as the mixed oxides obtained after calcination were studied by several physic-chemical techniques: N2-Sorption, XRD, H2-TPR. The mixed oxides were also tested for the toluene total oxidation. The physico-chemical studies revealed modifications in the structural characteristics (surface area, morphology) as well as in reducibility properties of the formed mixed oxides. The solid containing the higher cerium content was the most active in this reaction. Furthermore, relation between the reducibility and T50 for the toluene oxidation was demonstrated, suggesting a Mars Van Krevelen mechanism for the toluene total oxidation with Co-Al mixed oxide. The key factor of these solids is the dispersion of the ceria in the solid.