High-performance doped carbon electrocatalyst derived from soybean biomass and promoted by zinc chloride

A high-performance doped carbon catalyst with a BET surface area of up to 949 m2 g−1 has been prepared by pyrolyzing soybean biomass with ZnCl2 as an activator, followed by acid leaching with H2SO4 and graphitization. For the cathodic reduction of oxygen, the catalyst exhibits excellent activity in an alkaline medium. Its onset potential and half-wave potential for the oxygen reduction reaction reach −0.02 V and −0.12 V (vs. Ag/AgCl) in 0.1 M KOH, almost comparable to those of commercial 20 wt% Pt/C catalyst. It is found that the addition of zinc chloride can significantly enhance the catalyst's surface area and activity. We suggest that the high performance of this type of catalyst is mainly contributed from its high active center density resulted from the high surface area of the catalyst, which is caused by the activation of zinc chloride.