NOVELTY - Preparation of hydrogen (I) comprises conducting a reaction between a hydride composition (A) and a hydroxide composition (B) to form (I) and an oxide composition (C), where (A) has one or more cationic species other than (I).    USE - The invention deals about a preparation of hydrogen from hydrogen storage materials, and preparation of source of hydrogen gas. The hydrogen is used as a fuel in fuel cells in power devices.    ADVANTAGE - The present invention provides an improved hydrogen storage composition, which is useful as a storage medium. The method reduces the overall energy requirement for a system of storing and subsequently releasing hydrogen. The method reduces the overall enthalpy changes associated with the hydrogen storage material system resulting in an improvement of the overall efficiency of the fuel cell systems. The hydrogen is used as a fuel in fuel cells, which minimizes the heating and cooling systems in mobile units (e.g. vehicles or electronic devices). The energy required for hydrogen production and recharge is relatively low, and vastly improved when compared to energy requirement of existing hydrogen storage systems. The method provides solid phase storage of hydrogen.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a method for releasing hydrogen from hydrogen storage materials comprising mixing a first hydrogen storage material with a second hydrogen storage material, where the first hydrogen storage material comprises (A) and the second hydrogen storage material comprises (B); and conducting a reaction between the first storage material with the second storage material for a time and at a temperature to produce a reaction product comprising an oxide material and hydrogen;    (2) a hydrogen storage composition having a hydrogenated state and a dehydrogenated state: in the hydrogenated state, the composition comprises a hydride and a hydroxide having one or more cationic species other than hydrogen; and in the dehydrogenated state, the composition comprises an oxide;    (3) a method of producing a source of hydrogen gas comprising liberating hydrogen from a solid hydrogenated starting material composition comprising a hydride and a hydroxide, by reacting the hydride and the hydroxide in a solid state reaction to produce a dehydrogenated reaction product and hydrogen gas;    (4) a mixture of a hydride and a hydroxide having cationic species other than hydrogen, each one characterized by promoting release of hydrogen from the other one in the presence of: a catalyst, elevated temperature, or both; and    (5) a power device comprising: a fuel cell that uses hydrogen as fuel; a storage unit containing a hydrogen storage material having a hydrogenated state and a dehydrogenated state, where the storage material releases hydrogen used as fuel in the fuel cell, where the hydrogenated state of the storage material comprises a hydroxide having a cationic species other than hydrogen and a hydride; and a filler passage associated with the storage unit for supplying hydrogen to the dehydrogenated storage material in the storage unit.