TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The composition is compacted to form a pastille or granular mass, and no organic matter is present.The weight contents of the alkaline borohydride and NH4Y is greater or equal to 90% relative to total composition weight.The preferred borohydrides are the Li and Na compounds.Preferred Process: The generation process comprises:(1) a homogeneous powdered or granular composition is prepared as described above;(2) the composition is agglomerated to form a compact material;(3) the compacted material is placed in a combustion chamber; and(4) combustion is initiated by an appropriate heat source, which starts off an auto-sustained combustion with H2 generation to completion. Preferred Definitions:    Y = a nitro or dinitramide ( -N(NO2)NO2 ) group.    EXAMPLE - Preparation of a solid composition of a mixture of NaBH4 and NH4NO3 in the proportions of 60 / 40.    A mixture of NaBH4 (90 g) and NH4NO3 (60 g) with KNO3 (7 wt.%) as phase stabilizer additive was milled and then homogenized.    Part of the powdered mixture obtained was compacted under a pressure of 107Pa to a pastille form. The circular pastille formed (5 mm diameter, 80 mg wt.) was placed in a combustion chamber (vol 100 cm3), provided with a manometer, thermometer and flame initiator consisting of a nickel filament (80% Ni /20% Cr).The pastille was contacted with the filament then the camber purged with N2 at 105 Pa. The filament was then heated by Joule effect to initiation of the composition. Once initiated, the reaction was self-sustaining and was complete after 3 seconds.    The combustion temperature was 1044degreesK. On completion of combustion, the chamber was cooled to ambient and the pressure noted. The pressure increase and analysis of the gases after combustion, by GC / MS, enabled the calculation of the mass yield of H2, found to be 8.2% (H2 liberated per g of composition).    A similar test on a 50 / 50 wt. composition of LiBH4 and NH4NO3 was carried out.    The results obtained were as follows:- Combustion temperature : 1500 K; % yield of H2: 11.8 ;