Fabrication of Fe3C caged in N doped carbon nanotube as a desirable ORR electrocatalyst by a facile method

The Fe 3 C encapsulated in nitrogen doped carbon nanotubes electrocatalysts (Fe 3 C@N-CNTs) are constructed derived from iron metal-organic framework (Fe-MOF) by a facile method. It is well accepted that the catalytic performance is dependent on the morphology of the electrocatalyst. Thus, here, the morphology of the carbon nanotubes is obtained by tuning the species of iron salt and the annealing temperature, the optimal material shows nanotube morphology and high surface area. Also, it is noted that FeNC-Cl/800 has higher N content compared to FeNC-NO 3 /800, indicating that Cl − favor in promoting nitrogen doping. In alkaline condition, the optimized Fe 3 C@N-CNTs catalyst exhibits more positive onset and half-wave potentials (0.98, 0.85 V vs RHE) than other contrast samples. Importantly, it displays a more positive onset and half-wave potentials of 0.82, 0.68 V vs RHE in acidic medium. It shows a 4e − pathway towards ORR, good capacity of stability and methanol tolerance in both alkaline and acidic media. The excellent electrocatalytic performance arises from various active sites (Fe 3 C and N doping), pretty morphology and hierarchically porous structure.