NOVELTY - Storing hydrogen in a cellular solid material present in the form of a monolithic carbon or porous ceramic comprises: (a) degassing the material under high vacuum and at temperature of 150-400 degrees C; (b) impregnating, at room temperature, the degassed material with a solution of a metal hydride in solution in an organic solvent comprising ethers; (c) drying the impregnated material with a metal hydride solution, where the drying is carried out under primary vacuum and room temperature; and optionally (d) repeating, one or more times, the steps (b) and (c) as above per se.    USE - The composite material is useful for: the production of hydrogen. The composite material is useful to supply hydrogen in a fuel cell running on hydrogen (all claimed).    ADVANTAGE - The process is suitable for industrial scale preparation. The hydrogen production and storage is easy.    DETAILED DESCRIPTION - Storing hydrogen in a cellular solid material present in the form of a monolithic carbon or porous ceramic comprising a hierarchical porous network comprising macropores having an average size (dA) of 1 mu m to 100 mu m, preferably 4-70 mu m; and micropores having an average size (d1) of 0.7-1.5 nm, where the: macropores and micropores are interconnected; and material is free of mesoporous network, comprises: (a) degassing the material under high vacuum and at temperature of 150-400 degrees C; (b) impregnating, at room temperature, the degassed material with a solution of a metal hydride in solution in an organic solvent comprising ethers; (c) drying the impregnated material with a metal hydride solution, where the drying is carried out under primary vacuum and room temperature; and optionally (d) repeating, one or more times, the steps (b) and (c) as above per se. INDEPENDENT CLAIMS are included for:    (1) composite material present in the form of carbon monolith or porous ceramic comprising a hierarchical porous network, where the micropores in composite material contain hydrogen in metal hydride form of crystalline, semi crystalline or amorphous; and    (2) production of hydrogen comprising a heating the composite material at at least 100 degrees C.