Fabrication and Characterization of Ti-doped Sodium Aluminium Hydrides for Reversible Hydrogen Storage
K-S Lin, Z-P Wang, C-T Hsieh, S-H Chan and A. Su
Yuan Ze University, TW
Ti-sodium aluminium hydride, Hydrogen storage material, micro-grinding, XANES/EXAFS
Sodium aluminium hydride (NaAlH4) is a member of the family of complex metal hydrides that are current interest for onboard lightweight hydrogen storage applications of hydrogen fuel cells on most transportation or 3C products. Therefore, the objective of the present work was to investigate the synthesis, characterization, and reversible hydrogenation/dehydrogenation kinetics of Ti-NaAlH4 composites freshly doped and ball milled with chloride of Ti as a catalyst. Experimentally, the Ti-NaAlH4 samples were formed under THF-doping techniques and then dried/ball milled for 2h by using a SPEX 8000 high-energy mill. All procedures were conducted in a nitrogen flowing glove box. The H2 storage capacity of Ti-NaAlH4 samples were conducted and measured by a TGA microbalance method. In addition, the synthetic mechanisms, fine structures, crystallinity of Ti-NaAlH4 were further identified by FE-SEM/EDS, XRD, XANES/EXAFS and SSNMR techniques. These data all showed that not any Ti atom substitutes in NaH, the final decomposition product for the alanate. Reaction products of completely reaction samples that were THF-mixed or mechanically milled are also studied. Formation of TiCl3 is found in mechanically milled materials, but not solution mixed samples, where bonding to THF likely stabilizers Ti-based nanoclusters. Ti atom in these clusters is activated in a high-energy mechanical milling process.
Back to Program
Nanotech 2007 Conference Program Abstract