Influence of the oxygen partial pressure on the reduction of CeO2 and CeO2-ZrO2 ceramics

Based on recent thermodynamic estimations on the CeO2-CeO1.5, CeO2-ZrO2 and CeO1.5-ZrO2 systems, isothermal sections of the ternary CeO2-ZrO2-CeO1.5 system are calculated in the 1300-1700 degrees C region. Additionally, the complex relation between the nonstoichiometry, gamma, in CeO2-y, the composition of the CeO2-ZrO2 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 degrees 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. (c) 2005 Elsevier SAS. All rights reserved.