Preparation of zirconia-ceria materials by soft chemistry

New zirconia-ceria materials were prepared by soft chemistry with thermal treatments at temperatures below 1000 degrees C. Samples were characterized by XRD, DTA-TGA, BET area measurements and oxygen storage capacity (OSC) measurements. For the preparation, cerium nitrate and different zirconium precursors were used: zirconyl nitrate or chloride for coprecipitation and zirconium propoxide for the modified sol-gel method. Both the structure and the texture of those solids depend on the synthesis and the zirconium precursor. For solids prepared by the modified sol-gel method, with a surface area of 60 m(2) g(-1), a new cubic phase (Zr0.25Ce0.75O2) is obtained, while an orthorhombic zirconia phase was identified for solids prepared either by coprecipitation or sol-gel methods. The sol-gel method was particularly efficient for preparation of Ce-Zr-O mixed oxides with high cerium contents. OSC values were significantly higher than in the case of coprecipitated oxides. (C) 1999 Elsevier Science B.V. All rights reserved.