Portal de Periódicos da CAPES

Concerning oxygen anions in a nitrate melt

1974; Elsevier BV; Volume: 19; Issue: 6 Linguagem: Inglês

10.1016/0013-4686(74)85075-9

1873-3859

J.D. Burke, D.H. Kerridge,

Gas Sensing Nanomaterials and Sensors

Previous electrochemical measurements of the equilibrium constants for the oxidation of oxide ions by nitrate melts and associated equilibria are shown to be supported by other recent non-electrochemical measurements and by thermodynamic calculations. However, the hypothesis that the oxide ion is stabilized by nitrate anions (to form pyro- or orthonitrate anions) is shown to be inadequate to explain the experimental electrochemical results obtained by many workers. The alternative hypothesis of oxide ion stabilization by silica not only explains the existing measurements but allows consistent equilibrium constants to be calculated from existing data. The reaction between carbonate and powdered silica was shown to be rapid and to lead to a complex silicate but reaction with glass was found to be much slower. Similar differences in reactivity were observed with solutions of sodium peroxide. This kinetic stability of concentrated oxide, peroxide and hydroxide solutions in nitrate melts is thought to explain a number of other hitherto conflicting results.