Characterization of Pt supported on commercial fluorinated carbon as cathode catalysts for Polymer Electrolyte Membrane Fuel Cell

Abstract

Pt nanoparticles supported on carbon monofluoride (CFx), synthesized from H2PtCl6 using NaHB4 as a reducing agent has been investigated as a cathode electrocatalyst in fuel cells. Surface characterization, performed by transmission electron microscopy (TEM) and powder X-ray diffraction (PXRD), shows a homogeneous distribution and high dispersion of metal particles. Kinetic parameters for the electrocatalyst are also obtained from the steady state measurements using a rotating disk electrode (RDE) in 0.5 M H2SO4 solution. Analysis by Koutecky–Levich equation indicates an overall 4 e− oxygen reduction reaction (ORR). Evaluation of the catalyst in single cell membrane electrode assemblies (MEAs) for proton exchange membrane based Direct Methanol Fuel Cell (DMFC) and H2 Fuel Cell at different temperatures and flows of O2 and Air are shown and compared against commercial Pt/C as the cathode electrocatalyst. Evaluation of Pt/CFx in H2 fed fuel cells shows a comparable performance against a commercial catalyst having a higher platinum loading. However, in direct methanol fuel cell cathodes, an improved performance is observed at low O2 and air flows showing up to 60–70% increase in the peak power density at very low flows (60 mL min−1).