SYNTHESIS OF NANOSIZED CuO-CeO2 MIXED OXIDE BY CITRATE SOL-GEL METHOD

Abstract

Nano-particles of CuO-CeO₂ with the average particle size (10 - 40 nm) and surface area (45.3 m²/g) was obtained from a mixed solution of Ce(NO₃)₃, Cu(NO₃)₂, citric acid by the citrate sol-gel method as precursors. The characteristics of CuO-CeO₂ mixed oxide were examined by means of X-Ray diffraction (XRD), H₂-temperature-programmed reduction (H₂-TPR) and  the nitrogen adsorption and desorption (BET), transmission electron microscopy (TEM). The results indicated that there are CuO species in the CuO-CeO­₂ mixed oxide: the Cu²⁺ mostly exists in Cu_xCe_1-xO_2-dsolid solution, the left in the finely dispersed CuO species on the surface of CeO₂ and the bulk CuO. The calculating results from Powder Cell 2.4 software showed that, when CuO-CeO₂ mixed oxide was formed, the cell parameter values of CeO₂ was smaller than that of pure CeO₂, indicating that some Cu²⁺ entered the CeO₂ lattice.