Hydrogen halogen cell

Yeo, R. S. and McBreen, J. 1979. Transport properties of Nation membranes in elec-trochemically regenerative hydrogen-halogen cells. Journal of the Electrochemical Society 126 1682-1687. 

The Nafion membrane has been used as a separator in both the hydrogen-halogen cell (45,50) and in the zinc-bromine cell (38) because Nafion is a highly stable perfluorinated material which is not affected by strong acids and halogen. 

The overvoltage of the hydrogen halogen cell and the zinc-bromine cell is mainly contributed by the membrane resistivity, and this resistivity is a strong function of the electrolyte content in the membrane. It is clear that the membrane hysteresis effect will influence the cell performance. 

Jeo, R. S. and J. McBreen, Transport Properties of Nafion Membranes in Elec-trochemically Regenerative Hydrogen/Halogen Cells, Journal of the Electrochemical Society, Vol. 126, 1979, p. 1682. 

Perfluorosulphonic Nation membrane separators are used in direct contact with electrodes as solid polymer electrolytes (SPE) in fuel cells . In this case, the membrane is both the electrolyte and the separator. The use of perfluorosulphonic membranes as SPE started 30 years ago with the US space program Gemini and the realization of low temperature H2/O2 SPE fuel cells. Since then, the feasibility of operating the SPE fiiel cells on hydrogen/halogen couples has been demonstrated. In addition, the introduction of perfluorinated membranes for use in water and brine electrolysis and more recently in organic synthesis has taken place . 

To avoid low efficiency of the ORR in URFCs, other chemistries have been proposed. Thus, hydrogen—halogen regenerative fuel cell systems (Langer Sakellaropoulos,... 

Oxidation of sulphonamides in the presence of bromide or iodide ions and sodium methoxide in methanol also leads to formation of the N-halogeno intermediate. The nitrogen-halogen bond in these intermediates is weak and will undergo themiolysis. At -10 °C, reaction proceeds by base catalysed elimination of hydrogen halide and ftirther steps lead to an a-amino acetal 20. The reaction is carried out in an undivided cell and renders a-aminoacetals readily available for the iso-... 

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