Preparation and cell performance of Pt nanosheet catalyst layer for polymer electrolyte fuel cell Hiroshi Fukunaga (a*)
Department of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University
* fuku[at]shinshu-u.ac.jp
Abstract
Polymer electrolyte fuel cell (PEFC) is beginning to be used in practical applications such as fuel cell vehicles and residential cogeneration system. Its low operating temperature is suitable for rapid start up and shut down but supresses the reaction rate. Typically, carbon supported Pt (Pt/C) is used to enhance the oxygen reduction reaction at the cathode. However, since Pt is expensive and scarce, low Pt catalysts have been explored by many researchers. In addition, catalyst durability is beginning to be more of an issue since the use of PEFC in heavy-duty vehicle requires operation at high temperature. In this study, we focused on Pt-based nanosheet (Pt-ns) which is reported to have high mass activity and durability due to its flat structure consisting of few atomic layers. We developed two types of Pt-ns cathode, one is carbon supported Ru-core Pt-shell nanosheet catalyst (Ru@Pt-ns/C), originally developed by Takimoto and Sugimoto, and the other is non supported Pt nanosheet, developed by Takenaka et al. First, catalyst layer of Ru@Pt-ns/C was prepared by performing Cu underpotential deposition (UPD) and surface-limited redox replacement (SLRR) directly to the catalyst layer of Ru-ns/C, and it showed high fuel cell performance compared to the conventional electrode using Pt/C. Second, carbon-free ionomer-free Pt cathode was prepared by spray method and showed higher durability than Pt/C.
