The state-of-the-art of polymer electrolyte membrane fuel cell (PEMFC) technology is based on perfluorosulfonic acid (PFSA) polymer membranes operating at a typical temperature of 80 °C. Some of the key issues and shortcomings of the PFSA-based PEMFC technology are briefly discussed. These include water management, CO poisoning, hydrogen, reformate and methanol as fuels, cooling, and heat recovery. As a means to solve these shortcomings, high-temperature polymer electrolyte membranes for operation above 100 °C are under active development. This treatise is devoted to a review of the area encompassing modified PFSA membranes, alternative sulfonated polymer and their composite membranes, and acid−base complex membranes. PFSA membranes have been modified by swelling with nonvolatile solvents and preparing composites with hydrophilic oxides and solid proton conductors. DMFC and H2/O2(air) cells based on modified PFSA membranes have been successfully operated at temperatures up to 120 °C under ambient pressure...

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Approaches and Recent Development of Polymer Electrolyte Membranes for Fuel Cells Operating above 100 °C

Chemistry of intercalation compounds: Metal guests in chalcogenide hosts

Layered metal phosphates and phosphonates : from crystals to monolayers

Review on structural and chemical properties of transition metal phosphorous trisulfides MPS3

Properties of both amorphous and crystalline salts of tetravalent metals are reviewed, with special emphasis on the much studied salt of zirconium phosphate. The discussion includes: (1) method of preparation, (2) interlayered crystal structure, (3) effect of counter ions on interlayer distance and steric hindrance, (4) mechanism of ion exchange, and (5) the interaction of polar molecules. Other insoluble acid salts with a layered structure include the phosphates of titanium, hafnium, germanium, tin, lead, and the arsenates of titanium, zirconium, and tin. Fibrous precipitates of the insoluble acid salts of cesium and thorium phosphate are mentioned briefly. Under appropriate experimental conditions, insoluble acid of unknown structure can be obtained. Investigations of their crystalline structure may be highly desirable. The ion exchange capacities of many of these substances are evaluated. 80 references, 3 tables, 4 figures.

Syntheses, crystalline structure, and ion-exchange properties of insoluble acid salts of tetravalent metals and their salt forms

Formation region and structural model of γ-zirconium phosphate

Uptake of pyridine and n-butylamine by crystalline zirconium phosphate

Synthesis of the organic derivatives of γ-zirconium phosphate by the reaction with propylene oxide

New types of intercalated complexes are synthesized by the reaction of MPS3 layer crystals (M=Mg, Zn, Mn) with n-alkylamines (CnH2n+1NH2, n=1–8). The amines are adsorbed on the interlamellar surfaces of the MPS3 crystals to form two different types of complexes of increased values in basal spacing. The spacing value of the first type of complexes is independent of the number of carbon atoms in alkyl chain of the amines, and the value of the second type of complexes increases with the number of the carbon atoms. The possible arrangements of the amines in the interlayer region are proposed for these types of complexes.

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Masami Tanaka

Papers

Formation region and structural model of γ-zirconium phosphate

Uptake of pyridine and n-butylamine by crystalline zirconium phosphate

Synthesis of the organic derivatives of γ-zirconium phosphate by the reaction with propylene oxide

NEW INTERCALATED COMPLEXES OF MPS3 (M=Mg, Zn, Mn) WITH n-ALKYLAMINES

Exchange reaction of phosphoric ester ions with phosphate ions in a heterogeneous system containing the organic derivative of γ-zirconium phosphate