화학공학소재연구정보센터
Journal of Hazardous Materials, Vol.373, 141-151, 2019
An efficient mechanochemical synthesis of alpha-aluminum hydride: Synergistic effect of TiF3 on the crystallization rate and selective formation of alpha-aluminum hydride polymorph
alpha-AlH3 is one of the most promising hydrogen storage materials due to its high gravimetric hydrogen capacity and low dehydriding temperature. In present work, a convenient and cost-efficient solid-state mechanochemical reaction is proposed to obtain alpha-AlH3 nano-composite. With the addition of TiF3, alpha-AlH3 nano-composite was formed in a short period by milling of LiH and AlCl3. Based on XRD and NMR results, the average grain size of the alpha-AlH3 in the nano-composite was 45 nm. The reaction pathway as well as the synergistic effect of TiF3 on the solid state reaction between LiH and AlCl3 were confirmed. In the alpha-AlH3/LiCl nano-composite, TiF 3 reduced the temperature of dehydriding reaction and improved dehydrogenation rate of alpha-AlH3. Within the temperature range between 80 and 160 degrees C, dehydrogenation of the as-milled alpha-AlH3 nano-composite showed fast kinetics. At 160 degrees C, a maximum hydrogen desorption of 9.92 wt% was obtained within 750 s, very close to the theoretical hydrogen capacity of alpha-AlH3.