Hierarchically confined Pt3Co intermetallic nanoparticles in porous Co-N-doped carbon nanofiber for highly active and durable oxygen reduction reaction

The widespread commercialization of proton exchange membrane fuel cells (PEMFCs) is critically hindered by the lack of catalysts that are simultaneously active and durable for the oxygen reduction reaction (ORR). Herein, we report a robust electrospinning strategy to the synthesis of ultrafine Pt 3 Co intermetallic nanoparticles (2.6 nm), which are spatially confined within hierarchically porous Co-N-doped carbon nanofibers. The engineered architecture yields superior ORR performance, with a half-wave potential (E 1/2 ) of 0.926 V and a mass activity of 0.63 A mg Pt −1 , which represents a threefold improvement over commercial Pt/C. Crucially, durability assessments reveal a negligible loss of 8 mV in an E 1/2 after 30000 cycles, significantly outperforming the 20 mV degradation observed for Pt/C. A membrane electrode assembly incorporating the Pt 3 Co-CoNC cathode achieves a peak power density of 1.54 W cm −2 and retains 85% of its performance after accelerated durability testing. This work demonstrates that architectural confinement is a robust and effective strategy for designing catalysts that simultaneously achieve high activity and long-term stability, paving the way for advanced fuel cell applications.