A safe, portable, hydrogen gas generator using aqueous borohydride solution and Ru catalyst

A safe, simple, compact process generates high-purity hydrogen gas on demand from base-stabilized, aqueous solutions of sodium borohydride, NaBH4, by using a ruthenium, Ru, catalyst. These NaBH4-based solutions can store up to 7% hydrogen by weight. NaBH4 solutions do not generate significant amounts of H2 gas under ambient conditions. However, when in contact with Ru catalyst, NaBH4 solutions spontaneously hydrolyze to form H2 gas and sodium borate, a water-soluble, inert salt. When Ru catalyst is separated from the NaBH4 solution, H2 generation stops. This H2 generator promises to be safer, have quicker response to H2 demand, have a greater H2 storage efficiency, and be more easily controlled than commonly used H2 storage devices or generators. Nonflammable NaBH4 solutions can be easily coupled to provide H2 to internal combustion engines or fuel cell power systems.