Highly Active and Durable Transition Metal-Coordinated Nitrogen Doped Carbon Electrocatalyst for Oxygen Reduction Reaction in Neutral Media

Abstract

The major technical obstacles in commercialization of microbial fuel cell technology are the sluggish kinetic, high cost, and poor durability of an air cathode electrocatalyst. This research aimed to synthesize the highly active, stable and low cost non-precious metal catalyst to replace the expensive Pt electrocatalyst using a simple, low cost and scalable method. The Fe3C and Fe-N-C catalysts were prepared by direct heating the precursors under autogenic pressure conditions. X-ray diffraction pattern revealed the phase of Fe3C sample was cohenite Fe3C and graphitic carbon, while the phase of Fe-N-C catalyst was only graphitic carbon. The morphology of the synthesized catalysts was a highly porous structure with nanoparticle morphology. The surface area of the Fe3C and the Fe-N-C catalysts was 295 and 377 m2 g-1, respectively. The oxygen reduction reaction (ORR) activity of Fe-N-C catalyst was more active than Fe3C catalyst. The ORR performance of Fe-N-C catalyst exhibited about 1.6 times more superior to that of the noble Pt/C catalyst. In addition, the Fe-N-C catalyst was durable to operate under neutral media. Thus, a novel autogenic pressure technique was a promising method to effectively prepare an highly active and durable non-precious metal catalyst to replace the precious Pt/C catalyst.