Electronically conducting proton exchange polymers as catalyst supports for proton exchange membrane fuel cells - Electrocatalysis of oxygen reduction, hydrogen oxidation, and methanol oxidation

A variety of supported catalysts were prepared by the chemical deposition o f Pt and Pt-Ru particles on chemically prepared poly(3,4-ethylenedioxythiop hene)/poly(styrene-4-sulfonate) (PEDOT/PSS) and PEDOT/polyvinylsulfate (PVS ) composites. The polymer particles were designed to provide a porous, prot on-conducting and electron-conducting catalyst support for use in fuel cell s. These polymer-supported catalysts were characterized by electron microsc opy, impedance spectroscopy, cyclic voltammetry, and conductivity measureme nts. Their catalytic activities toward hydrogen and methanol oxidation and oxygen reduction were evaluated in proton exchange membrane fuel-cell-type gas diffusion electrodes. Activities for oxygen reduction comparable to tha t obtained with a commercial carbon-supported catalyst were observed, where as those for hydrogen and methanol oxidation were significantly inferior, a lthough still high for prototype catalysts. (C) 1999 The Electrochemical So ciety. S0013-4651(98)10-049-6. All rights reserved.