LiAlH4 was modified by mechanical milling and with the addition of 5 wt.% Fe2O3 in order to improve its hydrogen desorption properties. The composite was milled for 1, 3, 5, 7 or 15min, and depending on the milling time, various phenomena took place. Up to a milling time of 5min, the particle size of the composite decreases. Further milling leads to the particles agglomeration reaching the size of the starting material after 15min. Moreover, the mechanical milling process leads to the transformation of AlH - 4 to AlH 3 - 6 structure as a result of partial hydrogen desorption. Hydrogen desorption during the milling is the most pronounced in the sample milled for 15min, so this sample has only one hydrogen desorption peak in the temperature-programmed desorption measurements.Mechanical milling with the addition of Fe2O3 for up to 15min improves LiAlH4 hydrogen desorption properties as hydrogen desorption temperature and apparent activation energies decrease.

The effects of catalysis using vanadium as an additive (2 and 5 wt.%) in a high-energy ball mill on composite desorption properties were examined. The influence of microstructure on the dehydration temperature and hydrogen desorption kinetics was monitored. Morphological and microstructural studies of the synthesized sample were performed by X-ray diffraction (XRD), laser particle size distribution (PSD), and scanning electron microscopy (SEM) methods, while differential scanning calorimetry (DSC) determined thermal properties. To further access amorph species in the milling blend, the absorption spectra were obtained by FTIR-ATR analysis (Fourier transform infrared spectroscopy attenuated total reflection). The results show lower apparent activation energy (Eapp) and H₂ desorption temperature are obtained for milling bland with 5 wt.% added vanadium. The best explanation of hydrogen desorption reaction shows the Avrami-Erofeev model for parameter n = 4. Since the obtained value of apparent activation energy is close to the Mg-H bond-breaking energy, one can conclude that breaking this bond would be the rate-limiting step of the process.