Cd|KOH|NiOOH

Zn|NH4CI|MnO2

Li|LiClO4|MnO2

Pb|H2SO4|PbO2

H2|KOH|O2

фазовые диаграммы

The temperature influence on solubility in the ternary systems NaBO2–NaOH–H2O and KBO2–KOH–H2O

A study of the solubility in the ternary systems NaOH-NaBO2-H2O and KOH-KBO2-H2O is of special interest from a fundamental and practical point of view. These systems represent the discharged products of the borohydrides fuel cells. The performance of such mixtures is determined by the solubility of their components. Therefore, in the present work the solubility in the ternary systems was studied by means of isothermal saturation within 1 (H-50°C. The compositions of the equilibrium liquid and solid phases and compositions of the eulonic and perilonic equilibria, the coordinates of the homogeneous solution ranges have been determined. The systems with sodium and potassium ions considerably differ by the temperature influence on solubility of solid components.

Phase diagrams of the ternary systems NaBH4–NaOH–H2O, KBH4–KOH–H2O, NaBO2–NaOH–H2O И KBO2–KOH–H2O при -10°С

A study of the solubility in the ternary systems NaBH4–NaOH–H2O, KBH4–KOH–H2O, NaOH–NaBO2–H2O и KOH–KBO2–H2O is of special fundamental and practical interest. The first two systems are used as a fuel and as a hydrogen source in hydrogen power engineering that includes the low-temperature fuel cells; borohydrides are converted into metaborates. Hence, the last two systems represent the discharged by-product. The performance of such mixtures is determined by the solubility of their components, negative temperatures being especially critical. Therefore, in the present work the solubility in the ternary systems was studied by means of isothermal saturation at – 10°C. The compositions of the equilibrium liquid and solid phases and compositions of the eutonic and peritonic equilibria, and the coordinates of the homogeneous solution ranges have been determined. The best solubility of the solid components is characteristic of systems NaBH4–NaOH–H2O and KBO2–KOH–H2O.