Morphology Controlled Synthesis and Characterization of Vertically Aligned Carbon Nanofibers Supported Platinum Catalysts for Polymer Electrolyte Fuel Cells

The requirement for a fuel cell with an efficient three phase boundary (TPB) is one of the key challenges in the development of polymer electrolyte fuel cells (PEFCs). Vertically aligned carbon nanofibers supported platinum (Pt) electrodes, which ensure a large TPB area, low Pt loading, and high Pt utilization, are desirable for applications in PEFCs. The effects of a carbon support structure on the Pt particle formation and electrode electrocatalytic activity have been investigated. The results revealed that the density of carbon nanofibers has an extremely important influence on both the size and predominant crystallographic planes of the platinum catalysts due to the topography dependence of the Pt nanoparticle formation rate. It is crucial for preparing platinum catalysts with desired particle size, crystallographic planes, and as a result, excellent electrocatalytic performance. The Pt/VACNF-5 catalyst, which has the largest density of carbon nanofibers and ultralow Pt loading (10 μg cm–2) in this study, exhibits optimal electrochemical surface area (948 cm2 mg–1 Pt), Pt utilization (90.03%), and electrocatalytic activities toward methanol oxidation (1683 mA mg–1 Pt cm–2), suggesting a great potential for application in PEFCs.