Pt nanoparticle–nanowire hybrids supported on single-walled carbon nanotubes for enhanced oxygen reduction reaction in polymer electrolyte fuel cells

Abstract

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.