Local structure analyses of Ce_0.5Zr_0.5O₂ mixed oxides by XAFS

Three types of CeO₂-ZrO₂ with the same composition (Ce/Zr = 1) were prepared by different methods, exhibited the different oxygen storage/release capacity (OSC). To investigate the relationship between the OSC and the local structure, the Ce and Zr K-edges XAFS spectra for these samples were measured. The features of Fourier transforms of these samples were different from each other. This suggested that the OSC was remarkably exerted by the local structure around Ce and Zr. The quantitative curve-fitting analysis of EXAFS was applied, and it was concluded that homogeneous Ce_0.5Zr_0.5O₂ solid solution at atomic level exhibited the highest OSC among these CeO₂-ZrO₂ with the same composition (Ce/Zr = 1).