Highly Dispersed Cu-N-X Moieties Embedded in Graphene: A Promising Electrocatalyst towards the Oxygen Reduction Reaction

Transition metal-carbon-nitrogen catalysts for the oxygen reduction reaction (ORR) are promising and challenging. Cu is a potential transition metal to form efficient ORR catalysts for fuel cells. Herein, a facile method is developed to synthesize a highly dispersed Cu-N-X and N-doped graphene (Cu-N-G) catalyst. The Cu-N-G catalyst shows a half-wave potential (E-1/2) of 0.859 V, which is comparable to the commercial Pt/C catalyst (0.856 V), and is among the best compared with the previously reported Cu-based materials. In addition, such a catalyst shows good stability and methanol tolerance in alkaline media. A synergy of doped N (pyridinic and graphitic N) and Cu-N-X moieties as well as the pore structure are revealed to account for the enhanced ORR activity.