Synthesis of ceria-zirconia mixed oxide from cerium and zirconium glycolates via sol-gel process and its reduction property

Ceria–zirconia mixed oxide was successfully synthesized via the sol–gel process at ambient temperature, followed by calcination at 500, 700 and 900 °C. The synthesis parameters, such as alkoxide concentration, aging time and heating temperature, were studied to obtain the most uniform and remarkably high-surface-area cubic-phase mixed oxides. The thermal stability of both oxides was enhanced by mutual substitution. Surface areas of the CexZr1−xO2 powders were improved by increasing ceria content, and their thermal stability was increased by the incorporation of ZrO2. The most stable cubic-phase solid solutions were obtained in the Ce range above 50 mol%. The highest surface area was obtained from the mixed catalyst containing a ceria content of 90 mol% (200 m2/g). Temperature programmed reduction results show that increasing the amount of Zr in the mixed oxides results in a decrease in the reduction temperature, and that the splitting of the support reduction process into two peaks depends on CeO2 content. The CO oxidation activity of samples was found to be related to its composition. The activity of catalysts for this reaction decreased with a decrease in Zr amount in cubic phase catalysts. Ce6Zr4O2 exhibited the highest activity for CO oxidation. Copyright © 2006 John Wiley & Sons, Ltd.

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