Density Functional Theory Study of the Oxygen Reduction Reaction Mechanism on Graphene Doped with Nitrogen and a Transition Metal.

The active centers of carbon nonplatinum catalysts doped with cobalt, iron, nickel, and copper have been simulated by quantum-chemical density functional theory methods. The thermodynamics of the electrochemical oxygen reduction reaction (ORR) on model catalysts has been determined. It was found that among the studied catalysts, graphene doped with cobalt and iron showed the best properties. A two-state reactivity effect has been found on a cobalt-containing catalyst, and a more detailed reaction mechanism has been proposed, including the stages of charging by an extra electron and association with water. The proposed mechanism explains several effects that have arisen during the modeling in relation to the classical mechanism.