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Bifunctional catalyst was prepared by one-step pyrolysis of trimetallic ZIF. The obtained catalyst showed excellent charge–discharge stability in rechargeable Zn-air battery. • A facile and effect strategy is proposed for the synthesis of catalyst precursor. • This strategy reduces the adverse effects of the pyrolysis process on the catalyst. • The coexistence of Co NPs and CoFe-N x improves the ORR/OER activity. • The catalyst displays excellent durability as a cathode for Zn-air battery. Searching for high active, low cost and durable catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) remains challenge in developing metal-air battery cathodes. Herein, we proposed a novel bifunctional catalyst derived from the pyrolysis of Co/Fe/Zn trimetallic zeolitic imidazolite framework. The obtained Co@CoFe 0.01 N C catalyst displays desirable activity for both ORR and OER (E 1/2 = 0.844 V, E j=10 = 1.654 V). The Zn-air battery equipped with Co@CoFe 0.01 N C catalyst on the cathode exhibits a high peak power density of 174.1 mW cm−2, which is much superior than that of commercial 20% Pt/C (87.6 mW cm−2). Significantly, the designed Co@CoFe 0.01 N C presents an outstanding stability for over 100 h in rechargeable Zn-air battery. [ABSTRACT FROM AUTHOR]

The accessibility to highly active oxygen reduction reaction (ORR) catalysts with low cost is a priority for the rapid industrialization of Zn‐Air batteries. Herein, we propose a facile engineering synthesis of high‐activity quasi‐spherical Fe−N−C ORR nanocatalysts by chemical self‐assmbly. The morphological and structural features of the materials have been fully characterized. The synchrotron radiation techniques reveal that the targeted Fe−N−PQS‐900 with highly exposed Fe−Nx active sites well dispersed on the N‐rich micro‐nano carbon framework, endowing them with efficient access to oxygeneous species. The electrochemical measurements show its superior ORR catalytic performance to the commercial Pt/C catalyst, including a more positive half‐wave potential, smaller Tafel slope, better methanol‐tolerance capability, and more sustainable cycloability as well. An assembled Zn‐Air battery using the Fe−N−PQS‐900 as the cathode catalyst shows a specific capacity of 798 mAh g−1 with a power density of 114 mW cm−2 and an energy density of 958 Wh kg−1, enabling this non‐precious metal electrocatalyst very competitive in metal air fuel cell applications. [ABSTRACT FROM AUTHOR]

Sluggish oxygen reduction reaction (ORR) kinetics is the biggest obstacle in the development of metal air batteries. High-efficiency ORR catalysts with low cost are in urgent needs. Herein, we propose a robust Fe–N–C ORR catalyst with highly dispersed Fe-N x active sites on graphitic-N dominated porous carbon. The synchrotron radiation analyses reveal the discrete Fe-N x coordination derived from the Prussian blue (PB) while the graphitic-N doped porous carbon formed by pyrolysis of the polyaniline (PANI). In virtue of their synergistic catalysis, the tailored Fe–N–C catalyst shows a comparable catalytic activity and a better methanol-tolerance than the commercial Pt/C catalyst. The assembled Zn-Air battery demonstrates a specific capacity of 783 mAh g−1 as well as energy density of 917 Wh kg−1 at 10 mA cm−2, and a maximum power density of 112 mW cm−2 at 191 mA cm−2. A robust Fe– N –C ORR catalyst derived from PB-anchored PANI with well-dispersed Fe-N x active sites on graphitic-N dominated porous carbon host shows comparable performance to the commercial Pt/C catalyst. Image 1 [ABSTRACT FROM AUTHOR]