Emf measurements on nanocrystalline copper-doped ceria

Mixed oxide samples of nanostructured CuxCe1-xO2-y of various composition were generated by (i) chemical precipitation and ball milling and (ii) inert gas condensation. X-ray diffraction measurements suggested that copper oxide was dissolved in nanostructured cerium oxide up to concentrations of x = 11.15. Solid electrolyte cells of the type A, Cu2O/CuBr/CuxCe1-xO2-y (A = Cu or CuO) showed reversible cell voltages. The ratio of the formal chemical activities of CuO and Cu2O dissolved in nanostructured cerium oxide were calculated from the cell voltages. The results are discussed in terms of an apparent macroscopic solubility, due to interfacial segregation of copper oxide on nanostructured cerium oxide. (C) 1998 Academic Press.