High Oxygen Storage Ceria-Zirconia Solid Solutions Synthesized by Atmospheric Pressure Solvothermal Process

摘要

Ceria-zirconia solid solution is one of the most important components of three way catalyst (TWC) for cleaning automotive exhaust. Ceria-zirconia solid solution has a function as an oxygen storage material, which keeps air to fuel ratio (A/F) at the surface of TWC on a stoichiometric composition. The dissolved zirconia into ceria lattice makes cerium ions to be reduced easier and enhances especially bulk oxygen to release. However, there is a large difference of oxygen storage capacity (OSC) between a theoretical value and that of the prior ceria zirconia solid solutions. The cause of the large difference of OSC might be come from the inhomogeneous dispersion of Zr ions in ceria lattice. Atmospheric pressure solvothermal (APS) process was applied to ceria-zirconia solid solutions in this study. The APS ceria-zirconia showed excellent OSC. The excellent OSC performance was presumed to come from further uniformity of zirconium ions in the ceria lattice.