Engineering Pt Nanoparticles with Fe and N Codoped Carbon to Boost Oxygen Reduction Catalytic Performance in Acidic Electrolyte

While high cost and lack of long-term stability of Pt-based catalysts have been impeding their practical application in oxygen reduction reaction (ORR) in fuel cell technologies, iron and nitrogen codoped carbons (Fe–N–C) are appearing to be stable but unfortunately less-active catalysts in acidic electrolyte. Herein, an in situ surfactant-free Pt deposition approach to fabricate Pt nanoparticles (NPs) onto well-designed Fe–N–C nanostructures for producing highly performing Pt/Fe–N–C catalyst for ORR in acidic electrolyte is reported. Physical and electrochemical characterizations uncovered that electron transfer from Fe–N–C to their supported Pt NPs would weaken the adsorption of O₂ on the Pt surface, therefore improving the intrinsic activity of Pt for ORR. On optimizing the Pt loading, the intrinsic and mass-specific activity data of Pt in Pt/Fe–N–C are maximized at ≈0.93 mA cm⁻² and 0.46 A mg⁻¹-Pt, respectively, much higher than those for commercial Pt/C (0.21 mA cm⁻², 0.19 A mg⁻¹-Pt). The Pt/Fe–N–C catalyst also shows an intriguing long-term stability during the accelerated durability test. A new avenue for taking the advantages of Pt and non-noble metal ORR catalysts is pointed for achieving much better ones to accomplish ORR in acidic electrolyte.