Journal of Power Sources, Vol.279, 28-35, 2015
Nitrogen-doped carbon nanotubes as catalysts for the oxygen reduction reaction in alkaline medium
A novel electrocatalyst for the oxygen reduction reaction (ORR) is fabricated by directly annealing oxidized carbon nanotubes and tripyrrolyl[1,3,5]triazine in nitrogen. The structural and chemical properties of the resultant N-doped carbon nanotubes (NCNTs) are systematically investigated. The electrocatalytic activity of the NCNTs towards ORR in O-2-saturated 0.1 M KOH electrolyte is evaluated using rotating disk electrode voltammetry. The results demonstrate that the as-prepared NCNT-900 (annealed at 900 degrees C) exhibits excellent electrochemical performance towards ORR in alkaline medium with an onset potential of -0.038 V (vs Ag/AgCl), a high kinetic current density of 31.26 mA cm(-2) at -0.25 V, a dominant four-electron transfer mechanism (n = 3.88 at -0.25 V), and excellent methanol tolerance and durability. The results obtained are significant for the development of N-doped carbon-based electrocatalysts for alkaline fuel cells.