Redox Properties of Ordered Macroporous Ce-Zr Mixed Oxides

Abstract

In this contribution finely textured three-dimensionally ordered macroporous (3DOM) mixed oxides of composition Zr 0.6 Ce 0.4 O 2 were prepared by the inverse opal technique. By using thermal analysis and photoelectron spectroscopy the oxygen storage and the redox response to different environments has been investigated. Multiple high temperature oxidation-reduction cycles decrease the initial high sensitivity of the surface oxidation state of Ce to the environment. This has been ascribed to the development of Ce(III) phases. Finally, we present a simple analysis of XPS data that allow the detection of surface inhomogeneities on Ce-containing oxides. We show that phase segregation can produce chemically heterogeneous surfaces.