Cobalt molybdenum (Co-Mo) carbides were prepared by the carburization of Co-Mo oxides at temperatures of 723-973 K in a stream of CH4/H-2] gas. The carburized catalysts were evaluated using a single-stack fuel cell and three-electrode cell. The results showed high activities for the anodic electrooxidation of hydrogen over the Co-Mo catalysts carburized at 873 and 923 K. The 873 K carburized Co-Mo catalyst had the highest activity and achieved 10.9% of the performance of a commercial Pt/C catalyst in a single-stack fuel cell. The XRD, TPC, TPR and XPS results showed that the Co-Mo oxycarbide in the bulk and on the surface are the active species for the hydrogen oxidation reaction. (c) 2008 Elsevier B.V. All rights reserved.