Abstract
The oxidation behavior of reduced CeO2 and CeO2-ZrO2 solid solution (CZS) was studied by measuring the weight and temperature change during oxidization, in the near-room-temperature range. A flaming oxidation at close to room temperature was observed in some of the reduced CZS. This oxidation takes place in the CZS reduced at much lower temperatures, 800°C and 1000°C, compared with CeO2, for which the temperature of 1400°C or so is required for the occurrence of the flaming oxidation. The oxidation was not observed in the CZS reduced at a temperature higher than 1200°C. The material, which exhibited the flaming oxidation, possessed a high oxygen storage capacity (OSC) and a large specific surface area. The dissolution of ZrO2 into CeO2 results in an increase of OSC and in the retardation of grain growth. These two effects lead reduced CZS to a flaming oxidation at close to room temperature.
