The physicochemical, surface and catalytic properties of pure and doped 0.25CuO-NiO solids prepared by sol-gel method were investigated. The dopant concentration was 2, 4 and 6 mol% ZrO2. The solids investigated were calcined at 400 and 600 degrees C. The techniques employed were XRD, EDX, TEM, surface excess oxygen, nitrogen adsorption at-196 degrees C and catalytic oxidation of CO by 02 using both static and flow methods. The results revealed that the investigated system dissolved 4 mol% ZrO2 by heating at 400 degrees C. This process was accompanied by a significant increase in the S-BET and V-p with subsequent decrease in the (r) values of the doped adsorbent. ZrO2-doping of the system investigated followed by calcination at 400 and 600 degrees C led to a considerable increase in its catalytic activity in CO oxidation by 02 using static and flow methods. The doping process was not accompanied by any change in the activation energy of the catalyzed reaction. (c) 2007 Elsevier B.V. All rights reserved.