Improved Electrocatalytic Performance of Tailored Metal-Free Nitrogen-Doped Ordered Mesoporous Carbons for the Oxygen Reduction Reaction

Metal-free nitrogen-doped ordered mesoporous carbons were tailored from homemade mesoporous carbon CMK-3. The different amounts of N-doping were provided by using melamine as the nitrogen source at 900 degrees C. The corresponding electrocatalytic performance towards the oxygen reduction reaction (ORR) in alkaline media was evaluated. Prior to the thermal treatment, CMK-3 was modified by using nitric acid to introduce oxygen-containing functional groups. The results showed that the method employed is efficient to prepare N-doped carbon electrocatalysts. The amount of pyridinic-N reached a maximum value of 53.8 atom% in the Me/HNMK-5 catalyst material. The ORR performance of this material attained an onset potential of 0.92 V vs. RHE, and a half-wave potential of 0.87 V vs. RHE with a four-electron pathway in alkaline medium, comparable with the benchmark catalyst, 20 wt% Pt/C.