Cd|KOH|NiOOH

Zn|NH4CI|MnO2

Li|LiClO4|MnO2

Pb|H2SO4|PbO2

H2|KOH|O2

топливные элементы

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.

Heat balance analysis of solid oxide fuel cell battery

The paper analyzes the energy balance of the solid oxide fuel cell (SOFC) battery. The existence of three temperature points satisfying the equation of SOFC battery energy balance is found out. The first point is trivial and corresponds to the cooled state of the battery. The second temperature point corresponds to an unstable state of the battery and finally, the third point is stable and corresponds to the normal operating state of the battery. The difference between the third and second point defines the temperature interval within the battery is able to self-heating. Analogy with the Semenov diagram for chemical reactors is noted.

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.

Optimized catalysts for direct ethanol fuel cell

Ethanol electrooxidation catalyst PtSn (3:1, 40% Pt) on pyrolytic double-walled carbon nanotubes as a carrier was synthesized by means of modified polyol method. Electrocatalytic activity of the synthesized catalyst in model conditions (0.5М H2SO4 + 1М С2Н5ОН) is higher than that for analogous catalyst on XC 72 carbon and equals to 70 mA/mgcat (E = 0.4 V). Tolerant cathode catalysts based on nonmetal (S, P, Bi) modified Pt and platinum-free cathode catalysts PdСо and RuСоSe were synthesized by means of high temperature method. Enhanced efficiency and tolerance of these systems were shown in oxygen reduction reaction in presence of ethanol. PdCo (20% Pd, 6% Co) and PtBi (9:1, 40% Pt) showed the highest ethanol tolerance. Model tests results have been confirmed by low temperature ethanol-oxygen fuel cell tests data for MEAs with considered catalysts.