Selective nitrogen doping in graphene for oxygen reduction reactions.

Nitrogen-doped graphene materials with abundant pyridinic and quaternary nitrogen species were selectively synthesized by thermal surface polymerization of nitrogen-containing aromatic molecules. Catalytic studies revealed that the oxygen reduction by nitrogen-doped graphene, containing pyridinic and quaternary nitrogen species, proceeds via a four- and two-electron reduction pathway, respectively, in alkali-based solutions.