Influence of TiB2 addition upon thermal stability and decomposition temperature of the MgH2 hydride of a Mg-based mechanical alloy

Intensive mechanical milling was used to synthesize a MgH2 (50 wt.%) + TiB2 (50 wt.%) composite. Thermal stability of the composite versus H-desorption was studied employing the thermodesorption spectroscopy (TDS) method. The TDS data have revealed that TiB2 addition decreases the dissociation temperature of the MgH2 hydride by about 50 °C. An X-ray photoelectron spectroscopy analysis has shown that TiB2 addition does not alter the surface chemical state of particles of the MgH2 hydride, a component of the composite under consideration. The effect of decreasing decomposition temperature of MgH2 due to addition of TiB2 has been attributed to catalytic influence of a TiB2 particle surface on processes of associative hydrogen desorption taking place on the surface of MgH2 particles, as well as to a higher degree of dispersion of magnesium dihydride provided by the presence of TiB2.