A series of xCeO2-Al2O3 samples of different CeO2 loading (x = 1‒12 wt.%) were prepared by impregnation of γ-alumina with aqueous solution of (NH4)3[Ce(NO3)6]. The effect of CeO2 content on the structure, textural and redox properties of xCeO2-Al2O3 samples was studied by using N2 adsorption-desorption isotherms, XRD, and TPR. It was shown that the increase of CeO2 content leads to a decrease in surface area and pore volume of mixed oxides caused by filling the pores with cerium oxide particles. XRD measurements detected an increase of CeO2 average particle size on increasing ceria content. The redox properties of xCeO2-Al2O3 oxides were modified by a consecutive reduction and oxidation treatment, which was more evident for 6- and 12-wt.% CeO2 samples. An enhanced reducibility upon reduction-oxidation treatment of xCeO2-Al2O3 oxides was revealed by formation of a phase of high oxygen mobility reduced at a lower temperature.

The authors kindly acknowledge financial support by the Bulgarian Science Fund through project FNI E02/16 as well as by bilateral collaborations of the Institute of Catalysis with Catholic University of Louvain la Neuve (Belgium) and Institute of Catalysis and Petrochemistry, Madrid (Spain).

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