Cobalt based non-precious metal catalysis were synthesized using chelation of cobalt (II) by imidazole followed by heat-treatment process and investigated as a promising alternative of platinum (Pt)-based electrocatalysts in proton exchange membrane fuel cells (PEMFCs) Transmission electron microscopy (TEM) X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements were used to characterize the synthesized CoNx/C catalysts The activities of the catalysts towards oxygen reduction reaction (ORR) were investigated by electrochemical measurements and single cell tests respectively Optimization of the heat-treatment temperature was also explored The results indicate that the as-prepared catalyst presents a promising electrochemical activity for the ORR with an approximate four-electron process The maximum power density obtained in a H-2/O-2 PEMFC is as high as 200 mWcm(-2) with CoNx/C loading of 20 mg cm(-2) (C) 2010 Elsevier Ltd All rights reserved