Nitrogen-doped ordered mesoporous carbon sphere with short channel as an efficient metal-free catalyst for oxygen reduction reaction

Abstract

Nitrogen-doped ordered mesoporous carbon spheres (N-OMCS) were fabricated by an efficient aqueous self-assembly process with F127 as a template, phenol resin and dicyandiamide (DCDA) as carbon and nitrogen sources respectively. It was found that the N-OMCS displayed the homogeneous nitrogen dispersion, well-defined monodispersed spherical morphology with ordered mesoporous structure as well as short channel. The prepared N-OMCS-1.5-900 showed good catalytic activity, excellent stability and resistance to methanol oxidation in oxygen reduction reaction (ORR). The significant electrocatalytic performance could be attributed to the formation of carbon spheres with ordered mesoporous structure and short channel, which not only facilitated the mass transfer, but also provided abundant active sites on the surface. In addition, the graphitic degree and the different nitrogen species of N-OMCS-1.5-900 also played an important role in ORR. The successful synthesis and application of N-OMCS could provide a feasible method for the fabrication of heteroatom-doped ordered mesoporous carbon nanospheres and may also boost the development of the efficient metal-free electrocatalysts.