Atomically Dispersed Co Atoms Stabilized by Nitrogen Species in Carbon Skeleton for Efficient Oxygen Reduction and Zn-air Batteries

Abstract

Atomically dispersed and nitrogen-coordinated single metal atom implanted into the carbon substrate holds great promise as Pt-liked catalysts for oxygen reduction reaction (ORR). However, the complicated synthetic procedures of single atomic catalysts heavily limit their widespread applications. Herein, the atomically dispersed Co stabilized by nitrogen species in carbon skeleton (Co-SAs/NC) is prepared by a controllable pyrolysis of the nano-confined Co-precursor, and further employed as alkaline ORR catalyst. The atomic configuration and electronic structure of Co-SAs/NC are systematic investigated by a wide range of advanced techniques, such as electron microscopic and X-ray absorption spectroscopy. As expected, Co-SAs/NC exhibites excellent ORR activity with a large onset and half-wave potentials, as well as good selectivity and favorable stability. More importantly, the outstanding ORR performances of Co-SAs/NC enable the assembled Zn-air battery to deliver a large specific capacity of 788.4 mAh gZn-1, a maximum power density of 233.6 mW•cm-2, and a long cycle life.