Pyrolyzing precursors containing iron, nitrogen and carbon elements is a commonly used process for syn-thesizing Fe-N-C catalysts for oxygen reduction reaction (ORR). Generally, aggregation of iron-based species is prone to occur because of a lack of chemical bonds between iron-based species and carbon matrix and synthesizing highly porous Fe-N-C catalysts is difficult because carbon skeleton is prone to collapse during pyrolysis. Herein, highly porous Fe-N-C catalysts with fine iron-based species are synthesized by selecting glucose as carbon source, FeCl3 as iron source, and urea-derived g-C3N4 as nitrogen source, iron anchoring and stabilizing species, and pore-forming template. The multi-role g-C3N4-derived catalyst synthesized at 1100 degrees C (Fe-N-C-1100) has fine iron-based species, large specific surface area (737 m(2) g(-1)), and extremely high pore volume (2.66 cm(3) g(-1)). Accordingly, Fe-N-C-1100 shows a larger half-wave potential (E-1/2 = 0.894 V), a higher stability (Delta E-1/2 = 6 mV) after 10,000 potential cycles in alkaline media, and a higher peak power density (P = 152 mW cm(-2)) when employed as ORR catalyst of zinc-air battery, which are all superior to those of the commercial Pt/C catalyst (E-1/2 = 0.864 V, Delta E-1/2 = 30 mV, P = 134 mW cm(-2)). The present work brings a new method for synthesizing highly porous Fe-N-C catalysts decorated with fine active sites for ORR. (C) 2020 Elsevier Inc. All rights reserved.