Effect of water on the thermal stability of alpha-aluminum hydride

Abstract

Water can significantly enhance the thermal spontaneous combustion and explosion hazard of alpha-aluminum hydride (α-AlH3). Thermal analysis suggested that, as the water content increased from 10% to 40%, the total reaction heat was increased by 68.3%. α-AlH3 with different water contents (10%–40%) underwent hydrolysis reaction and oxidation reaction with the activation energy of 57.9–68.7 kJ/mol and 88.3–107.6 kJ/mol, respectively. As the heating rate increased from 0.2 to 2 °C/min, the onset temperature, the peak temperature, and the maximum heat flow of the exothermic reaction were increased. As the storage temperature increased from 45 to 65 °C, the time to maximum reaction rate decreased from 5.16 to 0.84 h. Combining the results of SEM, XRD, XPS and thermal analysis, the reaction mechanism of α-AlH3 and water under isothermal and non-isothermal conditions was revealed.