A porous FeO_x, N co-doped carbon material as an efficient catalyst toward oxygen reduction reactions in both alkaline and acidic electrolytes

To replace the precious metal ORR (oxygen reduction reaction) electrocatalysts, many transition metals and N-doped carbon composites have been proposed in last decade and acquire a rapid development as the promising non-precious metal catalysts. Herein, Ketjenblack carbon was adopted as the carbon precursor and fully mixed with the polymeric ionic liquid (PIL) of HvimNO₃ and Fe(NO₃)₃. This mixture was thermally calcined at 900 °C to produce a porous Fe, N co-doped carbon material denoted as the FeO_x-N/C. Due to the fact that the PIL of HvimNO₃ can strongly combine and disperse Fe³⁺ ions, and NO₃⁻ will be thermally pyrolyzed to form the porous structure, the FeO_x-N/C catalyst displays high electrocatalytic activity toward ORR in both 0.1 mol L⁻¹ KOH and 0.5 mol L⁻¹ H₂SO₄ electrolytes. The FeO_x-N/C is used as the catalyst to assemble a zinc-air battery, which exhibits a peak power density of 185 mW·cm⁻². The superior electrocatalytic activity, wide pH range, and facile preparation approach jointly make the FeO_x-N/C a promising electrocatalyst for the fuel cells and metal-air batteries in the future.