Abatement of Carbon Monoxide over CeO2–CoOx Catalysts: Effect of Preparation Method

Four CeO2–CoOx catalysts (containing 20% ceria) were prepared by impregnation, precipitation-oxidation, co-precipitation and hydrothermal methods (IMP, PO, CP and HT, respectively). They were characterized by X-ray diffraction, high-resolution transmittance electron microscopy, N2 adsorption–desorption, X-ray photoelectron spectroscopy, and temperature-programmed reduction. The catalysts catalyzed CO oxidation in a continuous flow micro-reactor. These results demonstrate that the activity of CO oxidation depended on both the surface area of catalyst and dispersion of ceria. The IMP catalyst exhibited substantial dispersion of CeO2 on the surface of CoOx and therefore the easiest release of oxygen to oxidize CO.