Hydrogen desorption properties of MgH2/LiAlH4 composites

Abstract The hydrogen desorption properties of MgH 2 –LiAlH 4 composites obtained by mechanical milling for different milling times have been investigated by Thermal Desorption Spectroscopy (TDS) and correlated to the sample microstructure and morphology analysed by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The MgH 2 –LiAlH 4 composites show improved hydrogen desorption properties in comparison with both as-received and ball-milled MgH 2 . Mixing of MgH 2 with small amount of LiAlH 4 (5 wt.%) using short mechanical milling (15 min) shifts, in fact, the hydrogen desorption peak to lower temperature than those observed with both as-received and milled MgH 2 samples. Longer mixing times of the MgH 2 –LiAlH 4 composites (30 and 60 min) reduce the catalytic activity of the LiAlH 4 additive as revealed by the shift of the hydrogen desorption peak to higher temperatures.