Abstract
A series of ZnO and Fe2O3 modified ceria/alumina supports and their corresponding gold catalyst were prepared and studied in the CO oxidation reaction. ZnO-doped solids show a superior catalytic activity compared to the bare CeO2-Al2O3, which is attributed to the intimate contact of the ZnO and CeO2 phases, since an exchange of the lattice oxygen occurs at the interface. In a similar way, Fe2O3-modified supports increase the ability of the CeO2-Al2O3 solids to eliminate CO caused by both the existence of Ce–Fe contact surface and the Fe2O3 intrinsic activity. All of the gold catalysts were very efficient in oxidising CO irrespective of the doping metal oxide or loading, with the ZnO containing systems better than the others. The majority of the systems reached total CO conversion below room temperature with the ZnO and Fe2O3 monolayer loaded systems the most efficient within the series.