TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The catalyst comprises palladium, platinum, copper, cobalt, or nickel. The content of the catalyst is 1-50% based on the total weight of the catalyst/carrier.    TECHNOLOGY FOCUS - METALLURGY - Preferred Component: The alloy is magnesium series alloy, titanium series alloy, lanthanum series alloy, manganese series alloy, or iron series alloy.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The carrier is the expandable graphite. The expandable graphite is prepared by grinding a mixture of a layered graphite and an organic solvent, and drying the resulting ground mixture. The organic solvent is tetrahydrofuran. The content of the catalyst/expandable graphite is 5-50% based on the total weight of the hydrogen storage composite material. The content of the alloy is 50-95% based on the total weight of the hydrogen storage composite material. EXAMPLE - A titanium series alloy was produced by a vacuum electric arc smelting method, where metals were molten in vacuum and under high temperature according to a specified mole ratio. A commercially available natural graphite (2 g) was mixed with tetrahydrofuran (20 ml). A high energy ball mill method was used to grind the resulting mixture at room temperature for 9 hours. Then, the mixture was removed from the ball mill, dried at 140degreesC for 4 hours, and broken to obtain an expandable graphite powder. The produced expandable graphite powder (5.4 g) was dispersed in water (H2O, 150 ml) to form a suspension. Palladium chloride (PdCl2, 1 g) was dissolved in hydrochloric acid (2.5 ml) and H2O (6.25 ml). The PdCl2 acidic solution and the graphite suspension were mixed for a few minutes, added with sodium hydroxide (6.25 ml), and formaldehyde (8 ml) to form a precipitation of palladium (Pd) metal, so that the Pd metal was deposited on the surface of graphite. The solid was collected by filtration, and was subjected to water-washing and vacuum drying in sequence several times. The resulting solid was dried at 100degreesC in an argon (Ar) atmosphere for 4 hours to obtain Pd/expandable graphite. An alloy/Pd/expandable graphite was prepared by a mechanical fusion method including loading Ti0.8Zr0.3Mn1.4Mo0.05Cu0.05V0.2Cr0.2 alloy (1.8 g) , and the prepared Pd/expandable graphite (0.2 g) in a mechanical fusion device to perform fusion for 6 hours similar to the ball mill method. The addition of Pd/expandable graphite increased the hydrogen storage capacity of the alloy.