Ball-Milling Effect on Biomass-Derived Nanocarbon Catalysts for the Oxygen Reduction Reaction

Nano-carbon oxygen reduction reaction (ORR) catalyst having a large N atoms content derived from biomass has been widely studied recently in fuel cells. In this paper, yuba of high-protein (wt. 53 %) was employed as precursor to fabricate N self-doped porous carbon ORR electrocatalysts with high N content. In terms of ORR performance, Y-850 exhibited the optimal electrocatalytic activity among all the samples at different pyrolysis temperatures, which is comparable that of commercial 20 % Pt/C. The prominent ORR characteristic of Y-850 is mainly contributed by its high N content, especially high graphitic-N content. In order to further improve its ORR performance, ball-milling was conducted on Y-850 before and after pyrolysis. The results indicate that an appropriate ball-milling before pyrolysis can effectively increase the limited current density of ORR.