Possibilities of nitrogen-doped defects in graphene as catalytic sites of oxygen reduction reactions

Ikeda, Takashi; Chai, G.*; Hou, Z.*; Terakura, Kiyoyuki*

Polymer electrolyte fuel cells are one of the most promising power sources. However, their practical use continues to be hindered by the prohibitive cost of Pt-based catalysts required to facilitate electrode reactions at operating temperatures of 80C. Recently, a large number of groups have reported significantly high ORR activities of sp carbon-based materials doped with light elements such as N, B, S, etc., thus leading to much debate on the role of the doped light elements in the ORR activity. In this computational study, we inspect possible oxygen adsorption and reduction processes on various models of N-doped defective graphene using FPMD simulations. The dynamics of an O molecule solvated in water along with energetic considerations, indicates that the N doping in defective graphenes can enhance efficiently their catalytic activity depending on the detailed structure of defects as well as the position of N dopants.