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

I. ALESSANDRI; M. A. BAÑARES; M. FERRONI; L. E. DEPERO; P. FORNASIERO; F. C. GENNARI; N. HICKEY; M. MARTINEZ-HUERTA; T. MONTINI

TOPICS IN CATALYSIS

Springer

Año: 2006 vol. 41 p. 35 - 42

1022-5528

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.