N，P-Dual Doped Porous Carbon with Trace Level Co Doping As Highly Efficient Electrocatalyst for Oxygen Reduction Reaction

Abstract

Fuel cells and metal-air batteries are considered as the alternative clean energy devices in the future. Oxygen reduction reaction (ORR) is the key process among them for poor reaction kinetics, which has significantly limited the commercialization of these devices. So it is very important and necessary to seek efficient and inexpensive catalysts for the ORR. Since Dai’s group first reported that N-doped carbon nanotube showed high ORR performance, many researchers have developed many kinds of carbon materials. It has been accepted that heteroatom doping can effectively improve the activity of carbon materials. And also our group has successfully proved that the edge carbon was much active than the basal plane. In this work, we used a very simple method to prepare a novel carbon material with N, P-dual doping and much holes exposed on the surface. In addition, trace level Co doping in the carbon material forming Co-N-C active species can also enhance the ORR performance. On one hand, the doping can adjust the electronic structure of the near carbon atoms, which would induce more active sites for ORR. And on the other hand, the hole formed on the surface of carbon nanosheets would expose much edge sites and can improve the intrinsic activity of carbon. For the heteroatom doping and more exposed edge sites, the prepared carbon materials showed highly excellent ORR performance, nearly to that of commercial Pt/C. Figure 1