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Abstract: The development of anhydrous proton conducting membrane is important for the operation of polymer electrolyte membrane fuel cell (PEMFC) at intermediate temperature (100–200°C). In this study, we have investigated the acid–base hybrid materials by mixing of strong phosphonic acid polymer of poly(vinylphosphonic acid) (PVPA) with the high proton-exchange capacity and organic base of heterocycle, such as imidazole (Im), pyrazole (Py), or 1-methylimidazole (MeIm). As a result, PVPA-heterocycle composite material showed the high proton conductivity of approximately 10−3 Scm−1 at 150°C under anhydrous condition. In particular, PVPA-89mol% Im composite material showed the highest proton conductivity of 7×10−3 Scm−1 at 150°C under anhydrous condition. Additionally, the fuel cell test of PVPA-89mol% Im composite material using a dry H2/O2 showed the power density of approximately 10mWcm−2 at 80°C under anhydrous conditions. These acid–base anhydrous proton conducting materials without the existence of water molecules might be possibly used for a polymer electrolyte membrane at intermediate temperature operations under anhydrous or extremely low humidity conditions. [Copyright &y& Elsevier]

Abstract: Recently, membranes with high anhydrous proton conducting have been attracted remarkable interest for the application to the polymer electrolyte membrane fuel cell (PEFC). In this paper, we have investigated the anhydrous proton conductor consisting of alginic acid (AA), one of the acidic biopolymers, and imidazole (Im). This AA–Im composite material showed the proton conductivity of 2×10-3Scm-1 at 130°C under anhydrous conditions. Additionally, these AA–Im composite materials have the highly mechanical property and thermal stability. Furthermore, the biological products, such as biopolymer, are cheap, non-hazardous, and environmentally benign. The proton conductive biopolymer composite material may have the potential for its superior ion conducting properties, in particular, under anhydrous (water-free) or extremely low humidity conditions. [Copyright &y& Elsevier]