Structural investigation of Ce2Zr2O8 after redox treatments which lead to low temperature reduction

Structural investigations of various aliquots of Ce2Zr2O8 were conducted after application of well-defined redox treatments. The results indicate that specific redox procedures induce modifications in the ceria-zirconia mixed oxide, which lead to notable effects on the hydrogen uptake temperature during Temperature Programmed Reduction (TPR). Pyrochlore-type cation ordering is evident for an aliquot which exhibits a single low temperature peak during TPR. However, the cation ordering is not complete in this case. Furthermore, the analysis indicates less extensive pyrochlore-type cation ordering for an aliquot which shows a TPR profile in which there are two peaks, one at high temperature and one at low temperature. Finally, an aliquot that exhibits a single high temperature TPR peak shows no evidence of cation ordering. The trend in the promotion of reduction to low temperature is associated with the extent of the pyrochlore-type cation ordering.