Oxygen reduction reaction, Biomass-derived electrocatalyst, Single atom catalyst, Phosphorus dopant, Zn-air battery, Renewable energy sources, TJ807-830, Ecology, QH540-549.5

Exploiting non-precious metal catalysts with excellent oxygen reduction reaction (ORR) performance for energy devices is paramount essential for the green and sustainable society development. Herein, low-cost, high-performance biomass-derived ORR catalysts with an asymmetric Fe-N3P configuration was prepared by a simple pyrolysis-etching technique, where carboxymethyl cellulose (CMC) was used as the carbon source, urea and 1,10-phenanthroline iron complex (FePhen) as additives, and Na3PO4 as the phosphorus dopant and a pore-forming agent. The CMC-derived FeNPC catalyst displayed a large specific area (BET: 1235 m2 g−1) with atomically dispersed Fe-N3P active sites, which exhibited superior ORR activity and stability in alkaline solution (E1/2 = 0.90 V vs. RHE) and Zn-air batteries (Pmax = 149 mW cm−2) to commercial Pt/C catalyst (E1/2 = 0.87 V, Pmax = 118 mW cm−2) under similar experimental conditions. This work provides a feasible and cost-effective route toward highly efficient ORR catalysts and their application to Zn-air batteries for energy conversion.