Heterogeneity in Mixed Cerium Oxides and Its Influence on the Behavior of Gold Catalysts for the Selective Oxidation of Ethanol

Abstract

Mixed metal oxides have been investigated for a host of applications, yet many questions regarding the relationship between their material properties and their functional behavior remain unanswered. Mixed metal oxides are frequently used as support materials for catalytic processes, and the structure/composition of the oxide can significantly influence the behavior of a mixed oxide supported catalyst. In this article, we study the material properties of binary mixed cerium oxide supports synthesized with various metal additives and their corresponding influences on the behavior of gold catalysts for selective oxidation of ethanol. We have found that, although all of these materials exhibited X-ray diffraction patterns consistent with a pure cerium oxide phase, compositional heterogeneities were present in many of the samples, as indicated by time-of-flight secondary ion mass spectrometry and temperature-programmed-reduction techniques. Furthermore, the mixed cerium oxide supported gold catalysts demonstra...