Kinetics of Catalytic Hydrolysis of Aqueous and Aqueous-Alkaline Sodium Borohydride Solutions

The influence of temperature, as well as NaOH and NaBH₄ concentrations on the rate of catalytic hydrolysis is investigated. Finely dispersed powders of platinum and ruthenium on a titanium oxide carrier were used as model catalysts. The activation energies in an aqueous and aqueous-alkaline solutions of NaBH₄, equal to 60.5 and 53.2 kJ/mole for Pt/TiO₂ and 62 and 64.65 kJ/mole for Ru/TiO₂, respectively, were determined. It was found that with an increase in the concentration of NaOH, the rate of hydrogen generation with Ru/TiO₂ decreases, and with Pt/TiO₂ passes through a maximum in the range 0.5–2 M NaOH. It is shown that with traditional processing of kinetic data for determining the activation energy, its dependence on the sorption properties of the surface and the concentration of the solution is revealed.