A variety of unsupported cobalt catalysts was synthesized using the Pechini method and tested for CO2-free H-2 production via methane decomposition. In order to study the influence of the synthesis conditions on the properties of cobalt materials, the Cobalt:Citric acid (Co:CA) ratio was varied systematically (from 1:2 to 1:20). In addition, a study of the effect of the activation process on the catalyst activity was performed by activating the catalyst with H-2 or CH4. In both the activation processes, metallic cobalt with fcc structure was obtained, but the particle morphology varied with the activation treatment. The catalytic behavior was highly influenced when the reduction procedure was performed under methane atmosphere. For the Co:CA ratios, the best results were obtained with the catalyst prepared with a Co:CA 1:20 ratio reduced in presence of methane, which shows a production of 6.47 mol of H-2 per mol of cobalt even without deactivation behavior for 30 min of the reaction period. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.