N-doped carbon nanotubes supported Pt nanowire catalysts for proton exchange membrane fuel cells

The large-scale practical application of proton exchange membrane fuel cells (PEMFCs) is difficult to achieve if their performance and durability cannot be improved. We successfully synthesized N-doped carbon nanotube (NCNT) supported Pt nanowire catalysts (PtNW/NCNTs) using the soft template method with NCNTs as support. The results of transmission electron microscopy show that the Pt nanowires are uniformly loaded on the support (NCNTs). X-ray photoelectron spectroscopy reveals that the N atom doped on the surface is in the form of graphite N and pyridine N. The electrocatalytic activity of PtNW/NCNTs is studied via the half-cell electrochemistry test. The PtNW/NCNTs show better oxygen reduction reaction activity than commercial Pt/C catalysts. The results of the single-cell polarization experiment reveal that the performance of PEMFCs with PtNW/NCNTs is improved, and the maximum power density is 966 mW cm−2. After 500 h dynamic cycle durability test, the average voltage loss of the single cell is 3.6% for the PtNW/NCNTs catalyst and 7.2% for the Pt/C catalyst. The Pt/C catalyst demonstrates severe Pt nanoparticle growth and aggregation with a broad size distribution, the PtNW along with minimal changes observed. PtNW/NCNTs are a promising replacement to traditional Pt/C catalysts as electrocatalyst in PEMFC applications.