Open AccessInfluence of impurities of the transitional metals Fe, Ni, and Co on the hydrolysis kinetics of BH− 4 ions in alkaline solutions
Author(s) -
I. M. Gamayunova
Publication year - 2021
Publication title -
èlektrohimičeskaâ ènergetika
Language(s) - English
Resource type - Journals
eISSN - 1680-9505
pISSN - 1608-4039
DOI - 10.18500/1608-4039-2021-21-3-164-170
Subject(s) - borohydride , hydrolysis , impurity , chemistry , arrhenius equation , activation energy , cobalt , catalysis , inorganic chemistry , ion , nickel , kinetics , reaction rate constant , organic chemistry , physics , quantum mechanics
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 BH− 4 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; ∼1 ppm for cobalt). The strongest accelerating effect on the hydrolysis of BH− 4 ions was rendered by nickel impurities: self-hydrolysis was accelerated by 1.2 times for 1 ppm Ni. The ambiguous trend of the kinetic curves does not allow to accurately estimate the activation energy; however, the increased temperature enhances the catalytic effect of hydrolysis acceleration according to Arrhenius’ equation.