Structure and State of Copper Oxide Species Supported on Yttria-Stabilized Zirconia

The structure and state of the active component-copper species in zirconia-supported copper catalysts with yttria-stabilized zirconia as a support were investigated. Catalysts with different copper contents (2-10 wt % of Cu) prepared by an impregnation technique were characterized by X-ray diffraction (XRD) analysis, radial distribution function (RDF) of electronic density method, X-ray absorption fine structure (XAFS) analysis, UV-visible diffuse reflectance spectroscopy (UV-vis DRS), and X-ray photoelectron spectroscopy (XPS). It was established that a small amount of copper could be incorporated in the zirconia fluorite lattice, while the main portion of the copper was situated on the support surface as finely dispersed copper oxide chain clusters.