FeNxC nano catalytic network as well as preparation method and application thereof

The invention relates to the technical field of oxygen reduction electrocatalysts, in particular to a FeNxC nano catalytic network as well as a preparation method and application thereof. The preparation method comprises the following steps: adding m-phenylenediamine and concentrated hydrochloric acid into a SiO2 suspension, then adding (NH4) 2S2O8 and FeCl3 solutions, oxidizing m-phenylenediamine into poly (m-phenylenediamine), and coating the poly (m-phenylenediamine) on the surfaces of SiO2 nanoparticles to obtain a powder sample; carrying out high-temperature pyrolysis on the powder in an inert environment to obtain FeNxC/SiO2; diazonium benzoate and reduced iron powder are added into the FeNxC/SiO2, and benzoic acid groups are grafted to the surface of the FeNxC/SiO2; siO2 is removed, and FeNxC nano-particles with the surfaces modified with carboxyl are obtained; an EDC solution and an NHS solution are added, and carboxylic acid groups on the FeNxC nanoparticles are activated; and adding the amino modifi