Porous carbons embedded with nitrogen-coordinated cobalt as an exceptional electrochemical catalyst for high-performance Zn–air batteries

The development of non-noble, efficient, and durable catalysts to replace expensive Pt-based catalysts for boosting the oxygen reduction reaction (ORR) is always an imperative and challenging topic. Herein, a triazine-linked covalent framework was prepared by using a cobalt-centered porphyrin derivative via a facile ionothermal approach, which was readily converted to a series of porous carbons (termed Co/N-PCs) with high surface areas upon controlled thermal treatment. The cobalt atoms coordinated with nitrogen were uniformly dispersed within the resulting porous structures. Accordingly, such as-prepared Co/N-PCs exhibited high activity for the ORR with a positive onset potential of 0.91 V (vs. RHE) and half-wave potential of 0.83 V, as well as good methanol tolerance and long-time durability. When used as air cathodes for Zn–air batteries, high power density (158.9 mW cm−2) and specific capacity (797 mA h g−1) were achieved, outperforming commercial Pt/C.