Oxygen reduction reactions on pure and nitrogen-doped graphene: a first-principles modeling.

Based on first principles density functional theory calculations we explored energetics of oxygen reduction reaction over pristine and nitrogen-doped graphene with different amounts of nitrogen doping. The process of oxygen reduction requires one more step than the same reaction catalyzed by metals. Results of calculations evidence that for the case of light doped graphene (about 4% of nitrogen) the energy barrier for each step is lower than for the same process on a Pt surface. In contrast to the catalysis on a metal surface the maximal coverage of doped graphene is lower and depends on the corrugation of graphene. Changes of the energy barriers caused by oxygen load and corrugation are also discussed.