A series of Ce-Cu nanoparticle oxide catalysts were prepared by a modified reverse microemulsion method using a mixture of cerium and copper nitrate solutions and various precipitating agents ((NH(4))(2)CO(3), NaOH or tetrapropylammonium hydroxide). The obtained precursors were transformed into the mono-phase oxide forms by calcination in air atmosphere. The catalytic activity of the Cu(x)Ce(1-x)O(2) nanoparticles in the methanol and ethylene incineration depended on both copper loading and size of nanocrystallites. Optimal composition as well as morphology of the active catalytic Ce-Cu oxide systems were proposed. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.