Influence of the oxygen partial pressure on the reduction of CeO2 and CeO2ZrO2 ceramics

Based on recent thermodynamic estimations on the CeO2CeO1.5, CeO2ZrO2 and CeO1.5ZrO2 systems, isothermal sections of the ternary CeO2ZrO2CeO1.5 system are calculated in the 1300-1700 °C region. Additionally, the complex relation between the nonstoichiometry, y, in CeO2−y, the composition of the CeO2ZrO2 solid solution and the oxygen partial pressure (PO2) for different ZrO2 containing solid solutions CezZr1−zO2−x (with z=0.2, 0.5, 0.8) are evaluated from 600 to 900 °C. The relation between the degree of Ce+4 to Ce+3 reduction under different PO2 in the fluorite CeO2−y and CezZr1−zO2−x solid solutions at different temperatures can be used as a guide in the development of functional ceramics or assist in explaining their performance as function of the operating atmosphere and temperature.