Morphology Controlled Electrospun Fibers as the Catalyst Layer for Polymer Electrolyte Membrane Fuel Cells

The efficient operation of Polymer Electrolyte Membrane Fuel Cells (PEMFCs) largely relies on a costly and easily-degradable platinum catalyst layer. Although air spraying techniques has previously served as the main method of catalyst deposition, electrospinning deposition may provide a more promising method by granting users precise control over 3-D structures by manipulating fiber diameter, porosity, and alignment. 12wt% of poly(acrylic acid) (PAA) and Nafion (1:4 weight ratio) solution was used to obtain a semi-viscous base solution for electrospinning. Through Laser Optical Microscopy and Scanning Electron Microscopy, optimal fiber diameter of 1 μm was found when incorporated with Pt/C, allowing uniform catalyst nanoparticles attachment. The fuel cell performance tests indicate that the morphology optimized electrospun electrodes exhibited a 108% increase in max power output over air-sprayed electrodes of comparable loading. This enhancement is attributed to its unique interwoven surface morphology, which increases the specific surface area of electrode and promotes the efficiency of the reactant and proton transport to catalytic sites. Thus, electrospinning can be used as a potential strategy to improve power output of PEMFCs by altering the catalyst electrode morphology.