N-Doped porous tremella-like Fe3C/C electrocatalysts derived from metal–organic frameworks for oxygen reduction reaction†
N-Doped porous tremella-like Fe3C/C electrocatalysts derived from metal–organic frameworks (MOFs) were fabricated via a facile approach. The simply designed catalytic materials have unique fluffy multilayer interconnected porous morphology, which provides a large specific surface area and effectively prevents the agglomeration of nanoparticles. These special features create more active sites (Fe–Nx) on the surface of the electrocatalysts for oxygen reduction reaction (ORR) and the presence of the Fe–Nx active sites was verified via X-ray photoelectron spectroscopy. The effect of Fe intake through pyrolysis of MOFs materials was also studied and the composite with 0.04 g Fe source exhibited excellent ORR performance, a very small hydrogen peroxide yield, and followed the four-electron transfer pathway. The ORR activity of the electrocatalyst is comparable to that of commercial Pt/C, while the stability is even better than the latter in an alkaline solution. The facile method of preparing a multilayer porous N-doped tremella-like Fe3C/C electrocatalyst is a promising electrode material for a wide range of applications in fuel cells and metal–air batteries.