Red-blood-cell-like nitrogen-doped porous carbon as an efficient metal-free catalyst for oxygen reduction reaction

Abstract

A red-blood-cell-like nitrogen-doped porous carbon catalyst with a high nitrogen content (9.81%) and specific surface area (631.46 m2/g) was prepared by using melamine cyanuric acid and glucose as sacrificial template and carbon source, respectively. This catalyst has a comparable onset potential and a higher diffusion-limiting current density than the commercial 20 wt% Pt/C catalyst in alkaline electrolyte. The oxygen reduction reaction mechanism catalyzed by this catalyst is mainly through a 4e pathway process. The excellent catalytic activity could origin from the synergistic effect of the in-situ doped nitrogen (up to 9.81%) and three-dimensional (3D) porous network structure with high specific surface area, which is conducive to the exposure of more active sites. It is interesting to note that the catalytic activity of oxygen reduction strongly depends on the proportion of graphic N rather than the total N content.