Synthesis of high-surface area CeO2 through silica xerogel template: Influence of cerium salt precursor

Ceria nanosized oxides with high surface area were synthesized by means of a templating approach, using a porous silica xerogel with surface area as high as 718 m2/g. After impregnation of the silica template with the cerium salt solution and further calcination at 600°C, the final ceria oxide was recovered by dissolving the silica framework in NaOH solution. The effect of cerium counteranion, nitrate or chloride, on the textural and reduction properties of the ceria oxide was examined. Characterizations by BET and pore size distribution, XRD, TPR and SEM/EDX techniques were performed. The silica xerogel templated approach resulted in the preparation of ceria with surface area of 205 m2/g and very small particle size (~5 nm), when cerium chloride precursor was used. An enhanced reducibility, at temperature < 700°C, was also observed for the so obtained CeO2 sample. The results were discussed in terms of the influence of cerium choride and cerium nitrate thermal decomposition.