activation energy

Electrode processes occurring in a tubular solid oxide fuel cell were studied using the distribution of relaxation time (DRT) method. The conclusion about the localization of the processes and their nature was made by analyzing the capacitances of the processes and changing their activation energy because of sequential activation of the electrodes. The greatest contribution to the total resistance of the cell was made by cathodic processes at the electrode-contact and electrode-electrolyte boundaries.

The paper studies the influence of temperature (50–100°C) and alkalinity (C OH – = 2.33–9.53 M) of aqueous solutions on the hydrolysis (self-destruction) kinetics of borohydride ions BH₄^– Characteristic peculiarities of the kinetic curve have been established and formulae to approximate the temperature-concentration dependence of the hydrolysis rate are proposed. An increase in temperature leads to an increase in the rate constant k of borohydride hydrolysis, and the temperature dependence of k satisfactorily obeys Arrhenius' equation.

The influence of small amounts of the Fe, Co, and Ni impurities on the spontaneous hydrolytic process of borohydride was studied within a temperature range of 60–100°C. The object under study was a simulated solution containing 9.53 M of OH^? ions and 0.14 M of BH₄^? ions, used as a fuel for borohydride fuel cells. The rate constant k of borohydride hydrolysis for a small amount of impurities at different temperature was estimated. The lowest non-accelerating concentrations of the impurities were established ( ? 10 ppm for iron? ?