Title of article :
Structural characterization and oxygen nonstoichiometry of ceria-zirconia (Ce1−xZrxO2−δ) solid solutions Original Research Article
Author/Authors :
M. Kuhn، نويسنده , , S.R. Bishop، نويسنده , , J.L.M. Rupp، نويسنده , , H.L. Tuller، نويسنده ,
Issue Information :
دوهفته نامه با شماره پیاپی سال 2013
Pages :
12
From page :
4277
To page :
4288
Abstract :
The oxygen nonstoichiometry and crystalline structure of ceria-zirconia Ce1−xZrxO2−δ (CZO) (x = 0.05, 0.1, 0.2, 0.5, and 0.8) solid solutions, commercially used as oxygen storage materials, have been examined using thermogravimetry, X-ray diffraction, and Raman spectroscopy. In this study detailed data describing oxygen vacancy concentrations, obtained at intermediate to high pO2, are interpreted with the aid of point defect equilibria relationships. For cubic CZO (x ⩽ 0.2), the ease of reducibility dramatically increased with increasing Zr content, as reflected by an ultimate >40% decrease in reduction enthalpy, with a corresponding shift in onset of reduction to higher pO2. The impact of pre-existing oxygen vacancies on the larger reduction enthalpy found for Y doped CZO, as compared with this study, is discussed, as is evidence that Zr increases the electron migration energy in ceria by 50%. The reducibility of tetragonal CZO (x > 0.2) was found to increase following redox cycling. This enhanced reducibility is believed to be related to ordering and is partially negated by a high temperature (1000 °C) heat treatment.
Keywords :
Ceria-zirconia , Nonstoichiometry , Raman spectroscopy , Reducibility
Journal title :
ACTA Materialia
Serial Year :
2013
Journal title :
ACTA Materialia
Record number :
1147066
Link To Document :
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