The paper deals with the reactivity of RuO2/Co3O4/CeO2 nanoparticles prepared by a reverse micelle approach, which was precipitated by alkali-hydrolysis of RuCl3, Co(NO3)(2) and Ce(NO3)(2) and transformed into RuO2/Co3O4/CeO2 catalyst by calcinations in air at 400 degrees C. The catalysts were investigated with XRD, TEM. XPS, and BET techniques and were tested for oxidation of cyclohexene. The nano-catalyst exhibited high catalytic activities for the oxidation of cyclohexene to the corresponding alpha,beta-unsaturated ketone under heterogeneous condition. In order to obtain maximum conversion of cyclohexene, the reaction parameters, like reaction temperature and time, were optimized. Under the optimized conditions, a maximum of 97.7% cyclohexene conversion and 95% selectivity, was achieved with RuO2/Co3O4/CeO2 mixed oxide nano-catalyst. (C) 2010 Elsevier B.V. All rights reserved.