Mn/Ce nano-composite oxides containing different amounts of manganese (5, 9, 17, 23, 29, 34 wt% as MnO2) were prepared by impregnation method at various calcination temperatures. Effect of both thermal treatment and loading on the structural, surface and microstructure properties of the as prepared nano-composites was determined. The combined effect of manganese oxide and ceria, at different concentrations, strongly influences the previous properties of the nano-composite oxides, by dispersing the MnO2 phase and promoting the efficiency of the Ce4+- Ce3+ and Mn4+ - Mn3+ redox couples.
The thermal treatment and loading influenced the interaction between manganese and CeO
2 evidently. The incorporation of Mn ions into CeO2 crystal lattice resulted in weaker interaction between manganese and ceria on composite surface. Manganese loading at 400oC led to a slight increase in the ceria crystallite size which decreased by increasing the calcination temperature from 400 to 600oC. The sintering activation energy of ceria was evaluated to be 12kJ/mol for the MnO2/CeO2 nano-composite.