Catalyzed LiBH4 and MgH2 mixture for hydrogen storage

The hydrogen desorption/absorption of the 2:1 mole ratio of LiBH4 and MgH2 with and without a catalyst was investigated. In the case of the uncatalyzed LiBH4/MgH2 mixture, the first hydrogen desorption started at 50 °C. The amount of released hydrogen was 8.6 wt% at the first hydrogen desorption and dramatically reduced to 1.8 wt% at the tenth hydrogen desorption. The decrease in the hydrogen capacity in the subsequent hydrogen desorption may be due to the irreversibility of LiBH4. To investigate effects of a catalyst on the hydrogen desorption, 3 mol% of TiCl3, HfCl4, ZrCl4, or VCl3 was added to the LiBH4/MgH2 mixture. The lowest hydrogen desorption temperature, 260 °C, was from the sample with TiCl3. An amount of the catalyst also influenced the kinetics of the hydride mixture and 5 mol% seems to be an optimum amount of TiCl3 that resulted in the lowest hydrogen desorption temperature, 240 °C. In addition, the higher the amount of a catalyst, the lower the amount of the released hydrogen.