▎ 摘 要
Nitrogen-doped graphene is favored as a catalyst for oxygen reduction reaction (ORR) over rare metals. However, the effects of bonding state, nitrogen doped site and defects on catalytic conversion are still unclear. Here, we investigate oxygen reduction reaction using nitrogen-doped graphene with selective bonding state through pyridinic and graphitic nitrogen selective approaches. Both types show ORR activity and the catalytic reaction is clarified to be a four electron reaction path. Graphitic nitrogen with a low level of defects is found superior from the viewpoint of using single graphene sheet for the ORR application. Our investigation provides useful information for various applications using doped graphene. (C) 2016 Elsevier B.V. All rights reserved.