Pt nanoparticle-nanowire hybrids supported on single-walled carbon nanotubes for enhanced oxygen reduction reaction...

Enhancing catalyst durability is crucial for the advancement of Polymer Electrolyte Fuel Cells (PEFCs). In this study, a hybrid catalyst composed of Pt nanoparticles and nanowires supported on single-walled carbon nanotubes (Pt_NP+NW/SWCNT) is investigated. This unique nanostructure synergistically combines the high activity of nanoparticles with the enhanced electron transport and structural stability offered by one-dimensional nanowires and SWCNTs. Pt_NP+NW/SWCNT demonstrated excellent electrochemical performance, with a half-wave potential of 0.882 V, a mass activity of 380 A g_Pt^-1, and a specific activity of 935 μA cm^-2, owing to its one-dimensional nanowire structure that promotes active site exposure and electron transport. The catalyst also showed superior intrinsic activity and remarkable durability. Accelerated degradation tests revealed only a 22.1% decrease in maximum power density and a minimal 14.9% loss in electrochemical surface area (ECSA) after 60 000 cycles, outperforming both Pt nanoparticles coated with N-doped carbon on SWCNTs (Pt@NC/SWCNT) and commercial Pt/C catalysts. While Pt@NC/SWCNT exhibits better resistance to acid poisoning in half-cell tests due to its N-doped carbon shell, Pt_NP+NW/SWCNT is more durable under realistic operating conditions. These results highlight the importance of structural stability in long-term fuel cell operation and suggest that Pt_NP+NW/SWCNT is a promising candidate for practical PEFC applications.