Preparation of zirconia–ceria materials by soft chemistry

Abstract

New zirconia–ceria materials were prepared by soft chemistry with thermal treatments at temperatures below 1000°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 (Zr 0.25Ce 0.75O 2) 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.