Oxygen Reduction Reaction Activity of Thermally Tailored Nitrogen-Doped Carbon Electrocatalysts Prepared through Plasma Synthesis

Although nitrogen-doped carbon catalysts are promising candidates for oxygen reduction reactions (ORRs), the role of the nitrogen bonding structure, such as pyridinic-N, amino-N, and graphitic-N, on the ORR activity remains controversial. Furthermore, despite recent progress in tuning the C−N chemical bonding states within the carbon materials by using chemical vapor deposition and post heat treatment, a systematic evaluation of various N moieties remains challenging, owing to the differences in the thermal stabilities of different types of bonds. Herein, we successfully designed a method to tailor pyridinic-N, amino-N, and graphitic-N bonding in N-doped carbon nanoparticles fabricated through a plasma process combined with post heat treatment. Investigations on the electrochemical performance of the fabricated materials suggested that catalysts with dominant amino-N exhibited higher current density, where graphitic-N has a positive effect on the ORR onset potential. This synthetic strategy provides a simple and efficient approach for studying the relationship between the C−N bonding structure and the electrochemical performance of N-doped carbon catalysts.