A treasure map for nonmetallic catalysts: optimal nitrogen and fluorine distribution of biomass-derived carbon materials for high-performance oxygen reduction catalysts

Abstract

Heteroatom-doped porous carbon materials have shown promising prospects in the field of Zn-air batteries (ZABs) and fuel cells. However, the high-throughput preparation and instant screening of excellent oxygen reduction reaction (ORR) carbon materials have not yet been effectively performed. Inspired by machine learning, a series of nitrogen (N) and fluorine (F) co-doped porous carbon materials (NF-PCs) with tunable total N and F contents and N/F doping ratios are synthesized by employing nearly 30 kinds of environmentally friendly biomass as precursors. A regular mapping describing the relationship between the ORR activity, heteroatom content and doping ratio is explored, and demonstrates the distribution pattern of the optimal catalytically active regions (∼4.8% total N and F content and N/F atomic ratio of ∼3) of biomass-derived carbon materials. Moreover, the Zn-air battery assembled from the as-prepared catalyst continuously drives 210 LEDs for at least 24 hours. This work offers a high-throughput strategy for screening and preparing excellent ORR catalysts, a general index for evaluating the ORR activity of N,F-doped carbons, and a research paradigm for other heteroatom-doped carbon materials.