Abstract: A series of CeO2-TiO2 composite oxide samples with differentn(Ce)/n(Ti)were prepared by the sol-gel method. The phase structure, morphology, surface area, and redox properties of the composite oxide samples were investigated through N2 adsorption,X-raydiffraction, transmission electron microscopy, and temperature-programmed reduction, and their catalytic performance for CO oxidation was measured. The amorphous CeO2-TiO2 composite oxide was formed gradually whenn(Ce)/n(Ti)was higher than 0.10. Withn(Ce)/n(Ti)=0.10-0.30, the amorphous CeO2-TiO2 solid solution with high surface area was formed and exhibited the characteristics of neither CeO2 nor TiO2. Although CeO2-TiO2 had lower catalytic activity than either TiO2 or CeO2 for CO oxidation, the Pd/CeO2-TiO2 catalyst presented excellent performance for CO oxidation.

Key words: sol-gel method, ceria, titania, composite oxide, palladium, supported catalyst, carbon monoxide, oxidation