Manganese decoration tailored nitrogen doping for boosted oxygen reduction electrocatalysis of Co-NC

Increasing the oxygen reduction reaction (ORR) electrocatalytic performance of cobalt-nitrogen carbon (Co-NC) materials is highly desired for promoting their widespread application. Yet, it remains challenging due to the existence of activity gap between Co-NC and commercial Pt/C catalyst. Herein, an in-situ decoration strategy was proposed to construct a series of manganese tailored Co-NC (Co _x Mn-NC, where x represents the molar ratio of Co/Mn) electrocatalysts, which not only increased the content of active metal-N _x sites but also enhanced the graphitized degree of carbon skeleton. The optimal Co _0.2 Mn-NC exhibited higher half-wave potentials (0.868 V; 0.594 V) than Pt/C (0.838 V; 0.580 V) and robust catalytic stability in alkaline and neutral electrolytes, which was attributed to the tailored nitrogen doping and enhanced graphitized degree. Impressively, a magnesium-air battery driven by Co _0.2Mn-NC exhibited better discharging performance than one driven by Pt/C, with a high open circuit voltage (1.61 V), a large peak power density of 83.17 mW cm ⁻², and a long discharge time of> 87 h at 20 mA cm ⁻². This work highlighted the promising potential of Mn decorated Co-NC for ORR related energy conversion.