▎ 摘　　要

In this study, we use density functional theory to investigate the catalytic activity of graphene (G), single vacancy defective graphene (G(SV)), quaternary N-doped graphene (NG(Q)), and pyridinic N-doped graphene (NG(py), 3NG(py), and 4NG(py)) on Co(0001) substrate for an oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). The results show pyridinic N-doped graphene on a Co support exhibited better performance than the NG(Q) on a Co support and free-standing systems. According to the results, ORR intermediates (*OOH, *O, and *OH) become more stable due to the presence of a Co substrate. The single pyridinic (3NG(py)) layer placed on Co(0001) is the most active site. The overpotential for Co/3NG(py) is rather higher compared to pure Pt(111) catalyst (0.65 V). Therefore, pyridinic N-doped graphene with a cobalt support could be a promising strategy to enhance the ORR activity of N-doped graphene in PEMFCs.