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.

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Discovering a high performance, durable, and cost-effective oxygen reduction reaction (ORR) electrocatalyst is a key strategy for widespread use of the high efficiency and environmentally friendly fuel cell and metal-air battery technologies. Herein, we fabricate a high performance and durable metal free N and S dual-doped mesoporous carbon nanostructure (NS-VXC) ORR catalyst using solid state thermolysis at 700 °C for 1 h. The fabricated catalyst exhibits nanocarbon aggregated chain-like morphology with a high surface area and mesoporous structure. The amount of N and S dopants embedded in mesoporous carbon nanostructure is found to be 3.2 and 1.1%, respectively which significantly attribute to the synergistic effect of spin and charge density leading to not only superior ORR performance but excellent durability in the alkaline environment as well. Rotating ring disk electrode analysis reveals the codoped NS-VXC catalyst possesses a direct 4-electron transfer number pathway with extremely low peroxide intermediate content. Compared to the benchmark Pt/C catalyst, the fabricated NS-VXC catalyst generated 10 mV ORR performance outperform and negligible performance degradation after the 10,000 ORR cycling test. These results suggest that an innovative solid state thermolysis methodology can be a powerful nanomaterial fabrication technique to generate high performance and excellent durability electrocatalyst for green energy applications.