TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The metal hydride is sodium borohydride. The second average particle size is not more than about 25% of the first average particle size. The liquid that is not reactive with the sodium borohydride, is ammonia. The liquid that is not reactive with the sodium borohydride, comprises hydrazine and ammonia.Preferred Composition: (I) comprises a transition metal or rare earth metal catalyst comprising cobalt (II) chloride; a phase adjustment additive comprising a 1-6C primary alcohol; and an additive to lower the pH of the liquid reactant component comprising an organic or inorganic acid (preferably hydrochloric acid, hydrofluoric acid, nitric acid, acetic acid, sulfuric acid, citric acid, carbonic acid, phosphoric acid, oxalic acid and/or their partially ionized salts). The liquid that is not reactive with the metal borohydride comprises ammonia, hydrazine, tetraethyleneglycoldimethylether and/or triethyleneglycoldimethylether.Preferred Process: In the method of increasing the efficiency of a conventional solid metal hydride hydrogen-generating apparatus having a first efficiency, the step of increasing the surface area comprises grinding the conventional metal borohydride, which has a first average particle size, to form the increased efficiency metal hydride fuel having a second average particle size that is smaller than the first average particle size; the step of increasing the surface area further comprises combining the increased efficiency metal hydride particles having a second average particle size with a liquid that is not reactive with it, in the absence of a stabilizing agent; the step of increasing the surface area comprises forming a slurry of the increased efficiency metal hydride fuel by combining conventional metal hydride fuel with a liquid that is not reactive with it in the absence of a stabilizing agent. The slurry of the increased efficiency metal hydride fuel in the non-reactive liquid is sufficiently flowable to enable liquid transport in it. The conventional metal hydride fuel is partially dissolved in the non-reactive liquid, thus forming the increased efficiency metal hydride fuel. The metal hydride comprises sodium borohydride. The step of increasing the surface area comprises grinding the second average particle size of 0.5 mm or less, preferably 0.25 mm or less.