Electrochemical behaviour and glass formation in molten bisulphates
- Cite this article as:
- Ingram, M.D., Duffy, J.A. & Forbes, S.M. J Appl Electrochem (1971) 1: 53. doi:10.1007/BF00615747
Molten bisulphates form an interesting class of low-temperature fused salts which quench to form glasses; some technical and theoretical applications of these systems are discussed. The NaHSO4KHSO-4 eutectic (46.5% KHSO4, m.p. 125°C,Tg 25°C) is easy to study since at lower temperatures decomposition of the melt is retarded and supercooling readily occurs. The solvent properties of this eutectic towards both inorganic and organic solutes have been investigated. The oxidation states available to transition and post-transition metals were studied spectrophotometrically and voltametrically; the results show a very restricted pattern of redox chemistry. The (abbreviated) electrochemical series is V(V)/V(IV)>Mn(III)/Mn(II)>H(I)/H2(O)>Ag(I)/Ag(O)>Mo(VI)/Mo(V)> Hg(I)/Hg(O)>Cu(II)/Cu(O)>Zn(II)/Zn(O). The Hammett acidity function,H0, was measured as in the range −1 to −2. Various factors influencing redox reactions in the melt are discussed.