Reaction Pathway for Oxygen Reduction on FeN4 Embedded Graphene.

The detailed reaction pathways for oxygen reduction on FeN4 embedded graphene have been investigated using density functional theory transition-state calculations. Our first-principles calculation results show that all of the possible ORR elementary reactions could take place within a small region around the embedded FeN4 complex. It is predicted that the kinetically most favorable reaction pathway for ORR on the FeN4 embedded graphene would be a four-electron OOH dissociation pathway, in which the rate-determining step is found to be the OOH dissociation reaction with an activation energy of 0.56 eV. Consequently, our theoretical study suggests that nonprecious FeN4 embedded graphene could possess catalytic activity for ORR comparable to that of precious Pt catalysts.