Bimetal Metal‐Organic Frameworks Derived Hierarchical Porous Cobalt@Nitrogen‐Doped Carbon Tubes as An Efficient Electrocatalyst for Oxygen Reduction Reaction

Abstract The design and preparation of inexpensive, stable, and superior catalysts for the oxygen reduction reaction (ORR) are significant but challenging towards sustainable energy conversion technologies. Herein, a tubular template‐assisted strategy for fabrication of cobalt nanoparticles (Co NPs) embedded in one‐dimensional (1D) N‐doped porous tubular carbon composites (Co@N−CTs) is developed via in‐situ growth of bimetallic zeolitic imidazolate frameworks (ZnCo−ZIFs) on hollow polypyrrole (PPy) nanotubes surface. The PPy can not only act as a hollow tubular template, but also efficiently inhibit aggregation of Co NPs. Thanks to the 1D tubular interconnected networks and abundant micro‐/nano‐ porous tube wall structure, the as‐prepared Co@N−CTs catalyst achieves outstanding ORR performance with an onset potential ( E 0 ) of 0.982 V and a half‐wave potential ( E 1/2 ) of 0.864 V. Meanwhile, the Co@N−CTs catalyst also demonstrates superior durability with slightly decay of 3 % of initial current over 40000 s, as well as tolerance to the methanol. Furthermore, the Co@N−CTs cathode exhibits a large specific capacity (784 mAh g −1 ) and satisfying power density (116 mW cm −2 ) in a Zn‐air battery.