Preparation and Characterization of the Electrocatalysts of Cobalt Atom Anchored on Nitrogen-Doped Porous Carbon for Efficient Oxygen Reduction Reaction

Due to the high cost， scarcity and low stability limiting the widespread application of the precious metal group （PMG） electrocatalysts toward oxygen reduction reaction （ORR）， it is of vital importance to develop outstanding non-precious transition metal alternatives. Herein， a highly stable and efficient cobalt-based catalyst， Co-N-C， was synthesized via the pyrolysis of a precursor of Co（acac）2@ZIF-8， originating from Co（acac）2 and zeolitic imidazolate frameworks （ZIF-8）. The as-synthesized Co-N-C not only possesses well-defined dodecahedral shape with large surface area and pore volume but also shows the excellent electrocatalytic activity towards ORR. The Eonset and E1/2 in 0.1 mol/L KOH solution are 1.028 and 0.844 V（vs.RHE）， respectively. When injecting 5 mL of 1.0 mol/L methanol into the solution， there was almost no change in E1/2. After 5000 cycles， E1/2 has a slight decrease of about 15 mV.