Medium-temperature membrane fuel cells

Alberti, G. and Casciola, M. 2003. Composite membranes for medium-temperature PEM fuel cells. Annual Review of Materials Research 33 129-154. 

Ahluwalia R K, Wang X, Rousseau A and Kumar R (2004), Fuel economy of hydrogen fuel cell vehicles , J Power Sources, 130,192-201 Alberti G and Casciola M (2003), Composite membranes for medium-temperature PEM fuel cells , Annu Rev Mater Res, 33,129-154. 

Alberti G, Narducci R (2009) Evolution of permanent deformations (or memory) in Nafion 117 membranes with changes in temperature, relative humidity and time, and its importance in the development of medium temperature PEMFCs . Fuel Cells 9 410. 

DMFCs and direct ethanol fuel cells (DEFCs) are based on the proton exchange membrane fuel cell (PEM FC), where hydrogen is replaced by the alcohol, so that both the principles of the PEMFC and the direct alcohol fuel cell (DAFC), in which the alcohol reacts directly at the fuel cell anode without any reforming process, will be discussed in this chapter. Then, because of the low operating temperatures of these fuel cells working in an acidic environment (due to the protonic membrane), the activation of the alcohol oxidation by convenient catalysts (usually containing platinum) is still a severe problem, which will be discussed in the context of electrocatalysis. One way to overcome this problem is to use an alkaline membrane (conducting, e.g., by the hydroxyl anion, OH ), in which medium the kinetics of the electrochemical reactions involved are faster than in an acidic medium, and then to develop the solid alkaline membrane fuel cell (SAMFC). 

Carbon supported Pt and Pt-alloy electrocatalysts form the cornerstone of the current state-of-the-art electrocatalysts for medium and low temperature fuel cells such as phosphoric and proton exchange membrane fuel cells (PEMECs). Electrocatalysis on these nanophase clusters are very different from bulk materials due to unique short-range atomic order and the electronic environment of these cluster interfaces. Studies of these fundamental properties, especially in the context of alloy formation and particle size are, therefore, of great interest. This chapter provides an overview of the structure and electronic nature of these supported... 

Further progress is expected from new developments and combinations of processes. Thus, it would be possible to make the disposal of the gaseous (and highly pure) waste gas streams (residual propane content of the propylene feed) cost-effective and a source of electric power by connection to novel, compact, membrane fuel cells. Potential synergisms would also occur in the operating temperature of the cells (medium-temperature cells at 120 °C using the residual exothermic heat of reaction from the oxo reaction), the membrane costs by means of combined developments (e.g., for membrane separations of the catalysts [22]), and also in the development of the zero-emission automobile by the automotive industry. The combination of hydroformylation with fuel cells would further reduce the E-factor - thus approaching a zero-emission chemistry. ... 

C.H. Park, C.H. Lee, M.D. Guiver, Y.M. Lee, Sulfonated hydrocarbon membranes for medium-temperature and low-humidity proton exchange membrane fuel cells (PEMFCs). Progress in Polymer Science 2011, 36(11), 1443-1498. 

Geormezi M, Chochos CL, Gourdoupi N, Neophytides SG, Kallitsis JK (2011) High performance polymer electrolytes based on main and side chain pyridine aromatic polyethers for high and medium temperature proton exchange membrane fuel cells. J Power Sources 196(22) 9382-9390... 

The polymer electrolytes used for low-temperature proton exchange membrane fuel cells (PEMFCs) are fundamentally different from the polymer electrolytes used in batteries. Here, the polymer is a medium for a solvent, normally water, and it is mainly in the solvent that ion transport occurs. The polymer serves several functions, of which the most important is to provide mechanical stability and electrode separation in the fuel cell application. Since the fuel cell needs proton transport from the anode to the cathode, the polymer also contains proton donating groups, often sul-phonic acid (-SO3H). The prototype PEMFC membrane materials have been perfluorosulphonic acids (PFSAs), of which the most established membrane material is Nafion (Fig. 8.8). These consist of hydrophobic teflon -CF2-CF2- backbones, with fluorinated hydrophilic and acidic side-chains for Nafion -0CF2CF(CF3)0CF2Cp2S03H. 

Bormet, B., Jones, D. J., Roziere, J., Tchicaya, L., Alberti, G., Casciola, M., Massinelli, L., Bauer, B., Peraio, A. and Rumunni, E. 2000. Hybrid organic-inorganic membranes for a medium-temperature fuel cell. Journal of New Materials for Electrochemical Systems 3 87-92. 

G. Alberti, M. Casciola, L. Massinelli, and B. Bauer. Polymeric proton conducting membranes for medium temperature fuel cells (110-160 degrees C). Journal of Membrane Science 185, 73-81 2001. 

Alberti, G. Casciola, M. Palombari, R. Inor-gano-organic proton conducting membranes for fuel cells and sensors at medium temperatures. J. Membr. Sci. 2000, 172, 233. 

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