Solvothermal Fabrication of Nitrogen-Doped Carbon Nanoparticles as Efficient Catalyst for Oxygen Reduction in KOH Electrolyte

In this study, CCl₄, metallic K and melamine were adopted as precursors to prepare nitrogen-doped carbon nanoparticles via a facile solvothermal method, where the CCl₄ served as carbon source, K as strong reduction agent, and melamine as N source. The specific surface area of the synthesized carbon nanoparticles is 184.1 m² g-¹ with about 3.7 at.% N doping content. In addition, the electrochemical measurements indicate that the difference of half-wave potential of carbon nanoparticles is only 46 mV relative to commercial 20 %Pt/C and a 4e transfer dominates the oxygen reduction reaction process. The high activity for oxygen reduction could be ascribed to the successful N doping, especially the pyridinic N and graphinic N, and the hierarchical porosity structure containing mesorpores and macropores, which are favorable for the O₂ dissociation and electron/ion transport during the reaction.