Self-template synthesis of Fe–Nx doped porous carbon as efficient oxygen reduction reaction catalysts in zinc air batteries

Metal-nitrogen doped carbon materials (M/NCs) exhibit considerable potential as electrocatalysts for oxygen reduction reaction (ORR) in novel energy conversion and storage devices. Herein, the Fe–N x doped porous carbon catalysts (FeN x PCs) with three-dimensional (3D) pore structure are synthesized by in situ pyrolyzation of polypyrrole-coated Fe 2 O 3 (Fe 2 O 3 @PPy). Fe 2 O 3 derived from the iron-formate framework (Fe-FF) is partially dissolved to generate Fe 3+ for driving polymerization and served as template to form the 3D structure during polymerization. FeN x PCs exhibit satisfactory long-term durability and superior ORR activity ( E 1/2  = 0.89 V) compared to commercial Pt/C. The Zn-air battery (ZAB) assembled with FeN x PCs reveals excellent battery performance, including a high open circuit voltage of 1.50 V, peak power density of 155.4 mW cm −2 , and cycling stability with 500 cycles. The excellent ORR activity of FeN x PCs could be ascribed to the porous structure , Fe–N x active sites, and high defect level of FeN x PCs. This strategy can modulate 3D porous structure via self-template synthesis, which provides a novel insight for development of high-performance air cathode catalyst.