Development and characterization of electrospun carbon nanofibers for proton exchange membrane fuel cells

Official URL: http://risc01.sabanciuniv.edu/record=b1221503 (Table of Contents)

In this work, electrospinning was used to produce acrylonitrile based copolymer carbon nanofibers (CNFs) with Platinum (Pt) and Palladium (Pd) nanoparticles for use in proton exchange membrane fuel cells (PEMFC). Acrylonitrile was copolymerized with n-vinyl pyrolidinone (VPYR) with different ratios as a template the size and the distribution of nanoparticles. The polymer, metal salt and solvent mixture were electrospunned for producing metal salt bearing polymeric nanofibers. Polymeric nanofibers were then dipped in a reducing solvent to produce metal nanoparticle on/in the polymer nanofibers. In order to get carbon fiber, pyrolysis were conducted which was performed by heat treatment process that includes stabilization of electrospun nanofibers in air environment at 200 °C followed by carbonization in nitrogen environment to temperatures between 600 °C and 1200 °C with different heating rates. The diameters of carbon nanofibers were found in the range of 80 to 600 nanometers while the particle sizes were reduced up to 4 nanometers. The electrocatalytic surface area was achieved as 34,5m /g for Pt and 22,4m /g for Pd nanoparticles. Synthesized polymers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR), Simultaneus Thermal Analysis (STA) and Differential Scanning Calorimetry (DSC). Fiber morphologies and nanoparticle sizes were examined via Scanning Electron Microscopy (SEM), X-Ray Diffractometer (XRD) and Tunneling Electron Microscopy (TEM). Electrochemical performance of metal nanooarticles was evaluated bv means of cyclic voltammetrv (CV)