PtFe Nanoalloys Supported on Fe-Based Cubic Framework as Efficient Oxygen Reduction Electrocatalysts for Proton Exchange Membrane Fuel Cells

While Pt-based binary alloys hold promising potential as cathode catalysts in proton exchange membrane fuel cells (PEMFCs) due to their desirable properties compared with monometallic counterparts, their weak interactions with carbon support make them challenging for practical cell implementation. Here, the PtFe alloys are uniformly deposited onto the surface of Fe-Nx-enriched nanocubes (FeNC) via surface confinement and internal vapor phase etching. The combined action of PtFe alloy and FeNC support acts as the electronic structure modulator resulting in the optimized intermediate adsorption (revealed by density function theory calculations), thereby boosting intrinsic activity to oxygen reduction reaction (ORR) and simultaneously enhancing their interactions. The resultant Pt1Fe1 @ Fe0.5NC-900 catalyst with a low Pt loading (0.065 mgPt cm-2) exhibits excellent mass activity and stability toward ORR in acidic media. When incorporated into a PEMFC, it delivers a superior peak power density of 1.05 W cm-2 and satisfactory stability performance. The metal precursor confinement strategy enhances the dispersion of metal precursors on the surface of the support and restricts the size growth through electrostatic adsorption characteristics. The synergistic interaction between PtFe alloy nanoparticles and the FeNC support facilitates efficient and stable cathode catalysts for proton exchange membrane fuel cells.image