Nitrogen and Sulfur Dual Self-Doped Graphitic Carbon with Highly Catalytic Activity for Oxygen Reduction Reaction

The use of heteroatom-doped carbon materials in the oxygen reduction reaction (ORR) continues to be an attractive alternative to Pt-based catalyst. In this work, nitrogen and sulfur dual self-doped hierarchically micro- and mesoporous graphitic carbon catalyst was prepared by pyrolysis of methyl orange (Fe (III)) complex, followed by removing the metal species in acid. The catalyst shows high electrocatalytic activity, long-term stability and tolerance for methanol in both acidic and alkaline media. Especially, the catalyst exhibits superior ORR electrocatalytic activity than that of the commercial Pt/C (20 wt %) in 0.1 M KOH: 0.962 and 0.865 V (vs RHE) of onset and half-wave potential was obtained, which is 8/22 mV positive than that for Pt/C, respectively. Additionally, the catalyst exhibits much greater stability than Pt/C. Kinetics investigations show that the catalyst follows the efficient 4-electron pathway for ORR in both the alkaline and acidic electrolyte.