laser vaporization controlled condensation (LVCC) method and the chemical methods were used to prepare the nanoparticle catalysts. These catalysts are pure CO3O4, CuO and NiO. The effects of dopants La2O3, SM2O3, Y2O3, Au, Pt and Pd on the surface and catalytic properties of these catalysts were investigated. The dopant concentration was 6 mol%. The techniques employed were XRD, nitrogen adsorption at - 196 degrees C, oxidation of carbon monoxide by O-2 and TEM. The results obtained revealed that most of the catalysts prepared by LVCC method gave maximum conversion Of CO to CO2 at room temperature while the catalysts prepared by wet impregnation and sol-gel methods gave maximum conversion at high temperature ranged from 160 to 300 degrees C. The degree of crystallinity and the particle size of catalysts were examined by XRD and TEM, respectively. (C) 2007 Elsevier B.V. All rights reserved.