Sub-ambient CO oxidation over Au/MO x/CeO 2-Al 2O 3 (M = Zn or Fe)

Abstract

A series of ZnO and Fe 2O 3 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 CeO 2-Al 2O 3, which is attributed to the intimate contact of the ZnO and CeO 2 phases, since an exchange of the lattice oxygen occurs at the interface. In a similar way, Fe 2O 3-modified supports increase the ability of the CeO 2-Al 2O 3 solids to eliminate CO caused by both the existence of Ce-Fe contact surface and the Fe 2O 3 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 Fe 2O 3 monolayer loaded systems the most efficient within the series.