Structural studies of mesoporous ZrO$_{2}$-CeO$_{2}$ and ZrO$_{2}$-CeO$_{2}$/SiO$_{2}$ mixed oxides for catalytical applications

TL;DR

This study synthesizes mesoporous ZrO₂-CeO₂ and ZrO₂-CeO₂/SiO₂ oxides with ordered pore structures, aiming to enhance catalytic properties through controlled crystallinity and surface area, using templating and characterization techniques.

Contribution

It introduces a synthesis method for mesoporous ZrO₂-CeO₂/SiO₂ oxides with improved structural and textural properties for catalytic applications, highlighting the role of SiO₂ addition.

Findings

High CeO₂ content yields single-phase ceria-zirconia solid solutions.

SiO₂ addition enhances structural stability and reduction behavior.

Ordered mesoporous structures are achieved with templating.

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.