An efficient metal-free catalyst derived from waste lotus seedpod for oxygen reduction reaction

Abstract

The sluggish kinetics of oxygen reduction reaction (ORR) has severely impeded the application of fuel cell technology. Developing economical and efficient biomass-based catalysts derived from natural waste to replace the expensive noble metal catalysts is becoming an attractive strategy. However, biomass materials often have geographical and seasonal characteristics. Thus, developing diversified and available biomass-derived catalysts is significant for different regions. In this work, N, P-dual doped porous carbon materials derived from waste lotus seedpod with tunable specific surface areas and porous structure are skillfully fabricated. The optimized sample exhibits excellent oxygen reduction reaction activity with an onset potential of 0.87 V vs. RHE and a Tafel slope of 81 mV dec−1, showing the 4e‒ electrons transfer path in alkaline solution. It also exhibits much better stability and methanol tolerance than commercial Pt/C. High ORR performance is considered to be ascribed to the abundant N, P dispersion and the hierarchical porous structure.