High‐performance ORR Catalyst of N‐doping Carbon‐coated Cobalt Nanoparticles Synthesized by DC Arc Plasma

Abstract

Abstract It is necessary to develop the oxygen reduction reaction (ORR) catalysts with aid to promote sluggish electrochemical kinetics in some energy conversion systems, e. g . fuel cells or metal‐air cells. Cobalt‐nitrogen‐carbon catalysts get a lot of attention owing to their excellent ORR performance, durability and lower cost. In this study, the physical vapor condensation route of DC arc plasma was developed to prepare the carbon‐coated cobalt nanoparticles (Co@C NPs) as a prime precursor, which was then suffered from a N‐doping process to harvest the Co@C(N) NPs catalyst materials. The synthesized Co@C(N) NPs exhibit excellent ORR catalytic performances with overt merits, such as lower cost, easy preparation, high‐yield, with respect to the precious metal catalysts. It is indicated that the Co@C(N) catalysts show a higher onset potential (E onset ) of 0.99 V ( vs . RHE), the limiting current density (J m ) of 4.99 mA cm −2 , and the excellent durability with only 10 mV of negative shift generated in the half wave potential (E 1/2 ) after 5000 cycles. Synergistic effect between the Co core of Co@C(N) nanoparticles and the active N‐containing sites in carbon layers is responsible for the enhanced catalytic performance, meanwhile the unique core‐shell nanostructure can also effectively protect the catalyst from deterioration in work. The N‐doping carbon‐coated Co@C(N) nanoparticles synthesized by DC arc plasma technique becomes a new strategy for development of non‐noble metal electrocatalysts.