Zeolite framework stabilized copper(I) oxide nanoparticles (4.8 +/- 2.6 nm) were prepared for the first time by using a four step procedure: the ion exchange of Cu(2+) ions with the extra framework Na(+) ions in Zeolite-Y, the reduction of the Cu(2+) ions within the cavities of zeolite with sodium borohydride in aqueous solution, the dehydration of Zeolite-Y with the copper(0) nanoclusters, and the oxidation of intrazeolite copper(0) nanoclusters by O(2) at room temperature. Zeolite stabilized copper(I) oxide nanoparticles were thoroughly characterized by ICP-OES. XRD, HR-TEM. Raman, XPS, UV-vis spectroscopy and N(2) adsorption-desorption technique. (C) 2009 Elsevier B.V. All rights reserved.