Structural studies of mesoporous ZrO2-CeO2 and ZrO2-CeO2/SiO2 mixed oxides for catalytical applications

• New soft template syntheses of zirconia doped ceria (ZDC) with SiO2 were developed.
• An amorphous-crystalline phase transition was correlated to the mesoporous structure.
• High specific surface area was obtained.
• High reduction rate Ce3+ to Ce4+ at 500 °C under temperature programmed reduction (TPR).

In this work the synthesis of ZrO2-CeO2 and ZrO2-CeO2/SiO2 were developed, based on the process to form ordered mesoporous materials such as SBA-15 silica. The triblock copolymer Pluronic P-123 was used as template, aiming to obtain crystalline single phase walls and larger specific surface area, for future applications in catalysis. SAXS and XRD results showed a relationship between ordered pores and the material crystallization. 90% of CeO2 leaded to single phase homogeneous ceria-zirconia solid solution of cubic fluorite structure (Fm3¯ m). The SiO2 addition improved structural and textural properties as well as the reduction behavior at lower temperatures, investigated by XANES measurements under H2 atmosphere.

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