Development of Effective Cobalt Catalysts for Hydrogen-Generating Solid Phase Compositions Based on Sodium Borane

Abstract

Hydrogen-generating solid phase compositions based on sodium boran are promising systems for storage and transportation of hydrogen to be used for low-temperature fuel cells with proton-exchange membranes. Catalysts are added to the compositions in order to generate hydrogen at ambient temperature. The studies were focused on the influence of conditions of the cobalt catalysts preparation on the rate of gasgeneration. The efficiency of hydrogen evolution depended on the nature of the cobalt salt and pH of its aqueous solution where the active component precursor was reduced under the action of the hydride; these factors determined the composition, dispersion and magnetic behavior of the cobalt systems. The maximal rate of gas generation (505 cm 3 /min per 1 g of the composition containing 8.4 wt % of hydrogen) was observed in the presence of the sample reduced by sodium borane in a cobalt chloride solution with pH 1.3. The results obtained can be used to develop effective and inexpensive cobalt catalysts for generation of hydrogen from solid compositions based on sodium borane.