A series of polypyrrole (PPY)-modified carbon-supported Co(OH)2 catalysts [Co(OH)2-PPY-C] with different types of carbon supports and the PPY and Co(OH)2 contents are synthesized to investigate the effect of the CoNx and CNC sites on the oxygen reduction reaction (ORR). X-ray photoemission spectroscopy results reveal that the CoNx and CNC sites dominate the four- and two-electron transfer ORR, respectively. The carbon support and the PPY and Co(OH)2 contents of the catalysts determine the distribution of the CoNx and CNC sites. The competition between these two sites determines the overall electron number of the ORR. A direct borohydride fuel cell using an optimal Co(OH)2-PPY-C as the cathode catalyst exhibits a maximum power density of 550 mW cm鈭? at 80 掳C.