Preparation and characterization of nanostructured Ce0.9Cu0.1O2−δ solid solution with high surface area and its application for low temperature CO oxidation

Nanostructured Ce0.9Cu0.1O2−δ solid solution with high surface area was prepared by improved citrate sol–gel method with incorporation of thermal treatment under N2. The sample was characterized by TG–DSC, BET nitrogen adsorption, XRD and H2-TPR. Its catalytic activity for CO oxidation was tested. It was found that the improved method offered catalysts with higher surface area and smaller crystallite size, which led to higher catalytic activity for low temperature CO oxidation. H2-TPR measurement indicated that there were three CuO species in the Ce0.9Cu0.1O2−δ solid solutions: finely dispersed CuO species on the surface of CeO2, partial Cu2+ penetrated into CeO2 lattice and bulk CuO phase. The finely dispersed CuO species was regarded as the active site for the low temperature CO oxidation.