Nonprecious metal catalysts (NPMC) for the oxygen reduction reaction were prepared by surface modification of a carbon black with 5,6-diamino-1,10-phenanthroline through diazonium and benzimidazole coupling chemistry. Both methodologies covalently attach 1,10-phenanthroline to the surface. Oxygen-free cyclic voltammograms (CV) obtained for these modified carbons showed a clearly defined redox peak at ca. 650 mV versus normal hydrogen electrode, which we attribute to phenanthroline-type groups on the carbon surface. Introduction of Fe and subsequent pyrolysis at 700 degrees C under a NH3/N-2 atmosphere yielded catalysts that were highly active toward the oxygen reduction reaction. The redox peak at 650 mV was present in the oxygen-free CVs for the most active catalysts, though less intense. Nevertheless, this indicates the presence pyridinic-type active sites in the heat treated catalysts and may be a useful tool in the study of NPMC. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3541256] All rights reserved.