Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10568146 | Journal of Power Sources | 2005 | 7 Pages |
Abstract
Pure layered phosphates of varying crystalline phases and crystallinity and composites of gradient layers of zirconium phosphate in Nafion 117-membranes have been prepared. The proton conductivity and, in case of the composites, also the dynamic mechanical properties of these materials were measured under different conditions of temperature and humidity. Membrane-electrode assemblies with low platinum catalyst loading of 0.4 mg cmâ2 Pt at the cathode and 1.9 mg cmâ2 Pt-Ru at the anode were examined in a direct methanol fuel cell (DMFC) at medium temperatures (130 °C). The conductivity of the layered zirconium phosphates is superior to the titanium phosphates and increases with decreasing crystallite size. The electrical performance of the composites in a DMFC-environment is slightly decreased as compared to the unmodified membrane but taking the reduced methanol crossover into account, higher efficiencies can be reached with the zirconium phosphate modified membrane. Furthermore, the mechanical properties are significantly improved by the presence of the inorganic compound.
Related Topics
Physical Sciences and Engineering
Chemistry
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Authors
F. Bauer, M. Willert-Porada,