In the present study, the characteristics of cobalt (Co) dispersed on mixed nano-SiO2-ZrO) supports were investigated. The samples were prepared by impregnation of the cobalt precursor onto the various mixed nano-SiO2-ZrO2 supports. After calcination, the samples were characterized with different techniques. XRD revealed that the Co oxide species were highly dispersed on the various supports without changes in morphologies. The reduced Co metal atoms determined by the H-2 chemisorption apparently increased with the use of mixed nano-SiO2-ZrO2 supports. It was suggested that the presence of mixed nano-SiO2-Zr-2, supports facilitated the reduction of cobalt oxide species. (c) 2007 Elsevier B.V. All rights reserved.