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 nanotube (PtNP+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. PtNP+NW/SWCNT exhibits the highest half-wave potential (0.882 V), mass activity (380 A·gPt-1), and specific activity (935 μA·cm-2), attributed to its one-dimensional nanowire structure, which enhanced active site exposure and electron transport. The synthesized PtNP+NW/SWCNT exhibits superior intrinsic catalytic activity and remarkable durability. Accelerated degradation tests show only a 22.1% decrease in maximum power density and a minimal 14.9% loss in the electrochemical surface area (ECSA) after 60,000 cycles, outperforming both Pt nanoparticle with N-doped carbon shell on SWCNT (Pt@NC/SWCNT) and commercial Pt/C catalysts. While Pt@NC/SWCNT shows better resistance to acid poisoning in half-cell tests due to its N-doped carbon shell, PtNP+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 PtNP+NW/SWCNT as a promising candidate for practical PEFC applications.