Synthesis and application in oxygen reduction reaction of N-doping porous graphitic carbon from biomass waste

In order to enhance the corrosion resistance of carbon supported electrocatalyst under harsh operating conditions for Zn-air battery, a new type of 3D porous graphitic carbon catalysts are developed through catalytic graphitization of biomass waste combing with metal and nitrogen introduction. The obtained catalyst exhibits outstanding ORR (oxygen reduction reaction) performance by exhibiting same half-wave potential than that of commercial 20 wt% Pt/C in alkaline condition and higher current density, better stability, and better methanol tolerance. When assembled for rechargeable Zn-air batteries, the samples show a power density as high as 154 mW cm-2 with an excellent cycling stability greater than 90 h/270 cycles. A series of control experiments provide a new insight into the coupling role of porosity and the degree of graphitization in ORR catalytic process, that is, the balance of graphitization and porosity contributes to both high activity and good stability.