Facile Synthesis of Cobalt and Nitrogen Coordinated Carbon Nanotube as a High-Performance Electrocatalyst for Oxygen Reduction Reaction in Both Acidic and Alkaline Media

Using a facile technique, the cobalt and nitrogen coordinated carbon nanotubes (Co-N-CNTs) were prepared through the pyrolysis of urea with P123 as template and Co (OAc)(2) as Co precursor in one pot, wherein P123 promotes the formation of nanotubes and mitigates the aggregation of cobalt in the process of pyrolysis. The obtained Co-N-CNTs catalyst exhibits exceptional catalytic performance for oxygen reduction reaction (ORR), possessing low onset potential (0.974 V vs RHE in 0.1 M KOH and 0.950 V vs RHE in 0.1 M HClO4), high current density, and good endurance, as well as excellent methanol tolerance ability not only in acid media but also in alkaline media. Kinetic analysis reveals that ORR on Co-N-CNTs follows a direct four-electron transfer mechanism. The outstanding ORR catalytic performance of Co-N-CNTs is primarily ascribed to its well-constructed nanotube structure, in addition to high content of N and the existence of Co-N-x configuration.