Improving biomass-derived carbon with cobalt/cobalt oxide doping for oxygen reduction reaction

Biomass-derived carbons from cypress leave, vegetable sponge, and pine needle were successfully prepared. They present three dimensional honeycomb structures. Electrochemical measurements showed that the carbon derived from vegetable sponge had the highest performance towards oxygen reduction reaction. Furthermore, the effects of cobalt content on carbon from vegetable sponge towards the oxygen reduction reaction were investigated, and the highest activities were obtained on vegetable sponge-Co-4%. It presented four-electron pathway on vegetable sponge-Co-4%. Meanwhile, vegetable sponge-Co-4% exhibited more positive half-wave potential (0.77 V) and onset potential (0.86 V) than those of vegetable sponge-Co-2% and vegetable sponge-Co-6%. And vegetable sponge-Co-4% displayed even superior stability and better tolerance to methanol crossover effects than the commercial Pt/C (20 wt% Pt).