Hydrothermal synthesis of tin doped ceria-zirconia solid solutions with enhanced thermal stability and oxygen storage capacity

Abstract

A facile hydrothermal synthesis of tin doped ceria-zirconia (Ce_0.5Zr_0.43Sn_0.07O₂) solid solutions was carried out using Ce(NH₄)₂(NO₃)₆, Zr(NO₃)₃·2H₂O and SnCl₄·5H₂O as the starting materials. The synthesized Ce_0.5Zr_0.43Sn_0.07O₂ particles were characterized for their oxygen storage capacity (OSC) for automotive catalysis applications. For the characterization, X-ray diffraction, transmission electron microscopy and the Brunauer-Emmet-Teller (BET) technique were employed. The OSC values of all samples were measured using thermogravimetric-differential thermal analysis. Ce_0.5Zr_0.43Sn_0.07O₂ solid solutions with a BET surface area of 246 m² g⁻¹ exhibited a considerably high OSC of 1425 μmol-O g⁻¹. The incorporation of tin ions in the lattice of the ceria based catalyst greatly enhanced the thermal stability and OSC. The influence of cation radius on the thermal stability and OSC was also discussed.