TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Catalyst: The magnetic catalyst also comprises a second nano metal shell wrapping the first nano metal shell, where the first and second nano metal shells have different compositions and at least one of the first and second nano metal shells is iron, cobalt, or nickel. Preferred Components: The carrier comprises strong-acid or weak-acid anionic exchange resin, metal, or surface activated non-metal. The magnetic catalyst is applied in a hydrogen supply device which is connected to a fuel cell. The first and second nano metal shells comprise copper, iron, cobalt, nickel, ruthenium, palladium, or platinum. Preferred Method: When the carrier is strong-acid or weak-acid anionic exchange resin, then the step of forming the first nano metal shell wrapping the carrier surface is chemical reducing; and when the carrier is metal or surface activated non-metal, then the step of forming the first nano metal shell wrapping the carrier surface is electroless plating. The method also involves forming a second nano metal shell wrapping the first nano metal shell. EXAMPLE - IR-120 (RTM: an anionic exchange resin) (30 g) was added to a cobalt chloride solution (CoCl2.6H2O, 8.992 g/dL), and stirred for 60 rpm at room temperature, such that the acidic function of the resin surface chelated the cobalt ion. The unchelated cobalt ion on the resin surface was then washed by deionized water. The washed resin was added to NaBH4 solution to reduce chelated cobalt ion, thus forming a nano cobalt shell wrapping the resin surface. The resin was then washed by deionized water and dried at room temperature, and analyzed by SEM and XPS to determine the magnetic catalyst having a single-layered nano cobalt shell. The chelated cobalt amount on the catalyst surface was 30%. While the magnetic catalyst was added in 1.32N of the NaBH4 solution, the hydrogen releasing reaction occurred. The magnetic catalyst was recycled after the hydrogen releasing reaction was completed. The recycled magnetic catalyst was washed by deionized water to repeat the hydrogen releasing reaction. The hydrogen releasing reaction was carried out at least three times after the magnetic catalyst was recycled three times and all had almost 100% hydrogen releasing amount before 2000 seconds of the hydrogen releasing reaction.