Metal-nitrogen-carbon ( M-Nx-C ), possessing prominent advantages of high reactivity, high selectivity, facile synthesis, have presented potential to replace the conventional platinum-based catalysts. However, when these catalysts are used in the oxygen reduction process of fuel cells, the low active site density and insufficient durability restrict application. It is found that modulating the electronic structure and spatial configuration of the active site by doping with various metal/nonmetal elements can significantly enhance the oxygen reduction activity and stability of M-Nx-C catalysts,...
