Nitrogen-doped hollow macroporous carbon spheres with high electrocatalytic activity for oxygen reduction

The nitrogen-doped hollow macroporous carbon spheres (NHMCS) were synthesized by silica template using 3-ethyl-1-vinylimidazolium tetrafluoroborate ([VEIM]BF4) as the source of carbon and nitrogen. The as prepared NHMCS were characterized by scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller and elemental analysis. The results show that NHMCS have the ordered macroporous structure, high-surface-area as well as 1.7% nitrogen doped content. The typical electrochemical methods were used to study the activity of NHMCS for oxygen reduction reaction in alkaline media, and the results show that NHMCS possess better electrocatalytic activity and high resistance to the methanol crossover than commercial Pt/C via a four-electron pathway.