Small silver nanoparticles (less than 7 nm) supported on silica as well as silica modified with CeO2 were prepared by impregnation techniques, characterized by physical-chemical methods, and tested in dehydrogenation of ethanol into acetaldehyde. The addition of CeO2 was shown to increase the catalytic activity of the AgiSiO(2) catalyst. The close interaction of the CeO2 nanoparticles (3-5 nm) with supported silver nanoparticles increased the activity of the AgiCeO(2)/SiO2 catalyst in both dehydrogenation and oxidative dehydrogenation of ethanol into acetaldehyde due to participation of the Ag-CeO2 interface in the ethanol activation or/and the spillover of active oxygen. (C) 2016 Elsevier B.V. All rights reserved.