Synthesis of hollow ceria-zirconia solid solution particles by spray pyrolysis with organic ligands and its oxygen storage capacity

CeO₂-based materials have been explored as oxidative catalysts owing to the reversible oxygen absorption and release behavior. The catalytic property is stabilized by addition of ZrO₂ to form the solid solution. Hollow CeO₂-ZrO₂ solid solution particles were prepared by a spray pyrolysis method with organic additives, characterized by SEM, XRD and TEM, and evaluated for oxygen storage capacity (OSC). Spherical hollow particles with a size of about 500 nm formed, which were composed of about 10 nm nanoparticles. CeO₂-rich particles had cubic crystal structure, while tetragonal phase was included in ZrO₂-rich particles. The addition of organic ligands was effective to form uniform solid solution and increase specific surface area. The spray-pyrolysis temperature should be low to keep the specific surface area. At 50 mol% ZrO₂, although the specific surface area was not so high as 20 m²/g, the maximum OSC of 650 μmol-O₂/g was achieved. It was found that the OSC depends on ZrO₂ content and the oxygen release rate increases with specific surface area.