Oxygen Reduction Electrocatalysis Using N-Doped Graphene Quantum-Dots

First-principles investigations of the electrocatalytic activity toward the four-electron oxygen reduction-reaction in N-doped graphene quantum dots reveal that pyridinic and graphitic nitrogen are the most active sites with overpotentials of 0.55 and 0.79-0.90 V, respectively. This agrees with experimental findings. Our calculations account for van der Waals interactions, solvent effects, and describe the electrochemistry using standard hydrogen electrode model. The results show correlations between OH*, OOH*, and O* binding energies that impose a lower limit on the oxygen reduction overpotential.