Solubility and related equilibria in the KBO2 - H2O and KBO2 - H2O - KOH systems

Abstract

Potassium borohydride KBH4 is an attractive chemical hydride for H 2 generation and storage in portable fuel cell applications. Nevertheless, the control of the by-products, in terms of stability and solubility in aqueous solutions, is one of the limiting steps of the hydrolysis reaction of H2 release. We report here some physicochemical properties of concentrated KBO2 aqueous solutions: solubility and gravimetric density are measured as function of temperature between 10 to 80°C. The stability of hydrated metaborates KBO2.xH2O solid phases (with x = 4/3 and 4) in alkaline aqueous solutions is also evaluated at 20°C. © Owned by the authors.