TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method comprises (i) weighing platinum/carbon catalyst and aniline according to mass ratio of 1:1, taking aniline, iron precursor, cobalt precursor and ammonium sulfate according to mass ratio of 1:4:0.7:3, weighing iron precursor, cobalt precursor and ammonium sulfate, adding 0.5 mol/l aniline monomer into aqueous sulfuric acid solution, ultrasonically stirring for 20 minutes, adding platinum/carbon catalyst, continuously ultrasonically stirring for 24 hours, taking uniformly dispersed platinum/carbon catalyst, stirring at 0 degrees C, dissolving in 0.5 mol/l ammonium persulfate into aqueous sulfuric acid solution, dripping iron precursor and cobalt precursor into the mixed solution of platinum/carbon catalyst and aniline, where the dripping time is controlled to 30 minutes, stirring at 0 degrees C, continuously reacting for 24 hours, drying the product, and grinding to obtain polyaniline modified platinum/carbon catalyst; and (ii) placing the platinum/carbon catalyst in the tubular furnace, heating the tubular furnace to 900 degrees C under the protection of inert gas, controlling the flow speed of the inert gas is 200 ml/minute, maintaining the temperature at 900 degrees C for 1 hours, cooling the product, adding 0.5 mol/l product in aqueous sulfuric acid solution, stirring at 80 degrees C for 4 hours, centrifugally washing the product, drying, and grinding to obtain nitrogen-doped carbon layer modified platinum/carbon catalyst; (i) weighing platinum/carbon catalyst and aniline according to mass ratio of 1:1.5, taking aniline, iron precursor, cobalt precursor and ammonium sulfate according to mass ratio of 1:2:0.5:4, weighing iron precursor, cobalt precursor and ammonium sulfate, adding 1.5 mol/l aniline monomer into aqueous sulfuric acid solution, ultrasonically stirring for 30 minutes, adding platinum/carbon catalyst, continuously ultrasonically stirring for 28 hours, taking uniformly dispersed platinum/carbon catalyst, stirring at 10 degrees C, dissolving in 0.5 mol/l ammonium persulfate into aqueous sulfuric acid solution, dripping iron precursor and cobalt precursor into the mixed solution of platinum/carbon catalyst and aniline, where the dripping time is controlled to 60 minutes, stirring at 10 degrees C, continuously reacting for 48 hours, drying the product, and grinding to obtain polyaniline modified platinum/carbon catalyst; and (ii) placing the platinum/carbon catalyst in the tubular furnace, heating the tubular furnace to 900 degrees C under the protection of inert gas, controlling the flow speed of the inert gas is 500 ml/minute, maintaining the temperature at 900 degrees C for 1 hours, cooling the product, adding 2 mol/l product in aqueous sulfuric acid solution, stirring at 90 degrees C for 2 hours, centrifugally washing the product, drying, and grinding to obtain nitrogen-doped carbon layer modified platinum/carbon catalyst; or (i) weighing platinum/carbon catalyst and aniline according to mass ratio of 1:1, taking aniline, iron precursor, cobalt precursor and ammonium sulfate according to mass ratio of 1:4:0.7:3, weighing iron precursor, cobalt precursor and ammonium sulfate, adding 0.5 mol/l aniline monomer into aqueous sulfuric acid solution, ultrasonically stirring for 20 minutes, adding platinum/carbon catalyst, continuously ultrasonically stirring for 24 hours, taking uniformly dispersed platinum/carbon catalyst, stirring at 0 degrees C, dissolving in 0.5 mol/l ammonium persulfate into aqueous sulfuric acid solution, dripping iron precursor and cobalt precursor into the mixed solution of platinum/carbon catalyst and aniline, where the dripping time is controlled to 30 minutes, stirring at 0 degrees C, continuously reacting for 24 hours, drying the product, and grinding to obtain polyaniline modified platinum/carbon catalyst; and (ii) placing the platinum/carbon catalyst in the tubular furnace, heating the tubular furnace to 1000 degrees C under the protection of inert gas, controlling the flow speed of the inert gas is 200 ml/minute, maintaining the temperature at 1000 degrees C for 0.5 hours, cooling the product, adding 0.5 mol/l product in aqueous sulfuric acid solution, stirring at 80 degrees C for 4 hours, centrifugally washing the product, drying, and grinding to obtain nitrogen-doped carbon layer modified platinum/carbon catalyst. Preferred Components: The iron precursor is ferric chloride, ferric nitrate or ferric sulfate. The cobalt precursor is cobalt nitrate, cobalt sulfate or cobalt chloride. The inert gas is nitrogen or argon.