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

Abstract

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.