Highly active cobalt- and nitrogen-doped carbon derived from ZIF-67@melamine towards oxygen reduction reaction

In this work, highly active cobalt- and nitrogen-doped carbon (Co-N-C) materials were prepared for oxygen reduction reaction (ORR). The Co-N-C materials were synthesized through co-pyrolysis of ZIF-67 and melamine (ZIF-67@melamine). Detailed powder X-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy and thermo-gravimentry (TG) analyses suggest melamine could accelerate the decomposition of the ZIF-67 framework. Compared with CoNC derived from pure ZIF-67, the CoNC- x C 3 H 6 N 6 materials derived from ZIF-67@melamine exhibit more carbon defects, larger BET specific surface area, higher content of pyridinic-N and graphitic-N, resulting in the enhanced activity of the CoNC- x C 3 H 6 N 6 samples. The onset potential of CoNC-0.5C 3 H 6 N 6 -700 catalyst towards ORR is 0.96 V (vs. RHE) and the half-wave potential is 0.87 V (vs. RHE), which are close to the state-of-the-art commercial Pt/C. Besides, the electrochemical stability of the CoNC-0.5C 3 H 6 N 6 -700 catalyst is much higher than that of commercial Pt/C.