“…6 Among the various candidates, cobalt-based catalysts attract particular attention due to their low cost, abundant resources and great potential for multiple catalytic reactions due to their multivalent nature and structural diversity. [7][8][9][10] Various strategies such as nanostructure design, doping engineering and integrating with conductive substrate, have been commonly employed to increase the abundant reaction sites on special surfaces, promote the intrinsic activity of the active site, lower the overpotential or facilitate charge transfer. Although some cobalt-based compounds can exhibit either one or two activities toward the ORR, OER or HER with high performance in alkaline solution, it remains challenging to achieve triple redox reactions (i.e., ORR, OER, and HER) on a single active site or on a single catalyst with a low overpotential.…”