Structural studies of mesoporous ZrO${}_2$-CeO${}_2$ and ZrO${}_2$-CeO${}_2$/SiO${}_2$ mixed oxides for catalytical applications

Abstract

In this work the synthesis of ZrO${}_2$-CeO${}_2$ and ZrO${}_2$-CeO${}_2$/SiO${}_2$ 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 CeO${}_2$ leaded to single phase homogeneous ceria-zirconia solid solution of cubic fluorite structure (Fm$\bar{3}$m). The SiO${}_2$ addition improved structural and textural properties as well as the reduction behavior at lower temperatures, investigated by XANES measurements under H${}_2$ atmosphere.