Relationships between structural/textural properties and redox behavior inCe0.6Zr0.4O2 mixed oxides

The redox behavior and the structural properties of Ce0.6Zr0.4O2 mixed oxid es of high surface area and dense ceramic-type materials are compared. It i s shown that due to the insertion of ZrO2 into the CeO2 lattice the oxygen sublattice becomes significantly distorted: Zr-O coordination of the type 5 + 2 and 4 + 2 is found in the former and latter samples, respectively. The nature of these distortions is correlated with the origin of the sample an d it appears also to be related to the particle size of the Ce0.6Zr0.4O2 mi xed oxide. Noticeably, the reduction behavior of these samples as investiga ted by the temperature-programmed reduction method appears correlated with their structural properties. (C) 1999 Academic Press.