Rational design of highly efficient catalyst for ORR is critical for development of advanced air cathode in Zn-air cells and fuel cells. To optimize the ORR performance of Co based cathode, the structure of carbon nanotube from DCI-Co precursor could be controlled through modulate synthetic parameters. The optimized ORR catalyst Co@NCNT-700 exhibit larger BET area, higher content of Co-N x and graphitic N, which performance could be improved in further through Cu doping. The experiment data approved that the activity of Co-N x was enhanced by the synergistic effect with introduced Cu. Furthermore, the high-performance zinc-air batteries was fabricated with the bimetal catalyst CuCo@NCNT-700 as an air electrode. The high open-cycle potential (1.54 V) and peak power density (0.275 W.cm-2 at 0.474 A.cm-2) were achieved, which would be potentially used to develop next generation energy conversion devices.
Keywords: bimetal catalyst; nitrogen doping; oxygen reduction reaction; synergistic effect; zinc-air batteries.