Platinum electrodeposition for polymer electrolyte membrane fuel cells

A novel electrodeposition technique for preparing the catalyst layer in pol ymer electrolyte membrane fuel cells has been designed, which may enable an increase in the level of platinum utilisation currently achieved in these systems. This method consists of a two-step procedure involving the impregn ation of platinum ions into a preformed catalyst layer (via an ion-exchange into the Nafion polymer electrolyte), followed by a potentiostatic reducti on. The concentration of Nafion within the catalyst layer was found to have a significant bearing on the size of the platinum deposits. The preparatio n of catalyst layers containing a desired platinum loading should also be p ossible using this method. Surface areas of the platinum deposits were dete rmined using cyclic voltammetry. The prepared catalyst was compared with a conventional electrode made from E-TEK Pt/C. Scanning electron microscopy w as used to investigate the dispersion of the platinum particles. Platinum l oadings were determined quantitatively by atomic absorption spectroscopy. ( C) 2001 Elsevier Science Ltd. All rights reserved.