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Synthesis and Thermal Characteristics of Complex Metal Hydride: NaAlH4

Published online by Cambridge University Press:  26 February 2011

Bouziane Yebka
Affiliation:
Kelly Automotive and Technical Services Group
Gholam-Abbas Nazri
Affiliation:
GM R&D and Planning Center, MC: 480–102-RCEL, Warren, Michigan 48090
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Abstract

Complex metal hydrides of general formula, ABH4 (A = alkali metals, B = third group elements such as B, Al, Ga) are potential candidates as hydrogen storage media for transportation. Thermal decomposition of complex hydrides generates hydrogen at elevated temperatures. The by -products of the dehydrogenation process can be regenerated using gaseous hydrogen at suitable temperature and pressure. The initial steps of thermal decomposition of NaAlH4 may be more complicated from the decomposition pathway reported in the literature. Close examination using thermal analysis by TGA, DSC and XRD measurements over the temperature range 30–500°C showed that the initial evolution of hydrogen occurred at a slow rate at ∼80°C, prior to fast decomposition at 190°C and at 260°C. Four regions of weight loss and five major endothermic peaks were measured during the thermal analysis. The effect of heating rate on the thermal analysis response showed that a high resolution of the thermal processes could be achieved at higher heating rates. Thermodynamic data was obtained for the various steps in the decomposition process including the formation of intermediate phases Na 3AlH6, and NaH. We also found that the decomposition of NaH is highly pressure dependent probably due to the high compressibility of the diffuse H anion. The crystal-chemistry of NaAlH4 during decomposition has been established using X-ray diffraction analysis.

Type
Research Article
Copyright
Copyright © Materials Research Society 2004

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References

REFERENCES

1. Imamura, H. and Sakasai, N.. J. Alloys and Compd., 321, 810 (1995).Google Scholar
2. Hollemann, A.F., Wiberg, E., in: Lehbuch der Anorgansischen Chemie, Walter de Grayter, Berlin, 1169 (1995).Google Scholar
3. Bagdonović, B., Schwichardi, M.J., J. Alloys and compd., 253, 19, (1997).Google Scholar
4. Huot, J., Boily, S., Guther, V., and Schulz, R., J. of Alloys and Compd., 383, 304 (1999).Google Scholar
5. Zaluski, L., Zaluska, A. and Ström-Olsen, J.O.. J. Alloys and Compd., 290, 71 (1999).Google Scholar
6. Zidan, R.A., Takara, S., Hee, A.G., and Jensen, C.M., J. Alloys and Compd., 285, 119 (1999).Google Scholar
7. Thomas, G.J., Guthrie, S.E., Gross, K.J., DOE Hydrogen Program review, (1999).Google Scholar
8. Gross, K.J., Guthrie, S., Takara, S., and Yhomas, G., J. of All. and Comp., 297, 270 (2000).Google Scholar
9. Bagdonović, B., Brand, R.A., Marjonoviæ, A., Schwichardi, M.J., Tölle, J., J. Alloys and compd., 302, 36 (2000).Google Scholar
10. Ashby, E.C., and Kobetz, P., Inorg. Chem., 5, 1615 (1966).Google Scholar
11. Gavrilenko, V.V., Egorenko, G.A., Antipin, L.M. and Zakharkin, L.I., Russ. J. Inorg. Chem., 12, 317 (1967).Google Scholar
12. Dymova, T.N., and Bakum, S.I., Russ. J. Inorg. Chem. 12, 3190 (1969).Google Scholar
13. Dilt, J.A., and Ashby, E.C., Inorg. Chem., 12, 1230 (1972).Google Scholar
14. Claudy, P., Bonnetot, B., Chahine, G., Letoffe, J.M., Thermochim. Acta, 38, 75 (1980).Google Scholar
15. Bagdonović, B., German Patent # 195–26–434 (1995).Google Scholar
16. Zaluska, A., Zaluski, L. and Ström-Olsen, J.O.. J. Alloys and Compd., 298, 125 (2000).Google Scholar
17. Garner, W.E., F.R.S., , and Haycock, E.W., The thermal decomposition of lithium aluminum hydride, Proc. oy. Soc. A211, 335 (1952).Google Scholar
18. Mikheeva, V.I., Selivokhina, M. S., and Krykova, O.N., Dokl, Akad. Nauk SSSR, 109, 439 (1965).Google Scholar
19. Grachet, F.G., Etienne, J.J., Mayet, J., and Tranchant, J., Bull. Soc. Chim. Fr, 3799 (1970).Google Scholar
20. Ashby, E.C., French Pat. 1,235,680 (1960).Google Scholar
21. Clasen, H., Angew. Chem. 73, 322 (1961).Google Scholar
22. Zakharkin, L.I. and Garrilenko, V.V., Dokl. Akad. Nauk. S.S.S.R. 145, 793 (1962).Google Scholar
23. Ashby, E.C., Brendal, G.L. and Redman, H.E., Inorg. Chem. 2, 499 (1963).Google Scholar
24. Smith, M.B., and Bass, G. E., J. of Chemical and Engineering Data, 8, 346 (1963)Google Scholar
25. Dymova, T.N., Eliseeva, N.C., and Selivokhina, M.S., Dokl. Akad. Nauk SSSR, 148, 589 (1963).Google Scholar
26. Klingen, T., J. Inorganic Chem., 3, 1059 (1964).Google Scholar
27. Fasolino, L.G., J. of Chemical and Engineering Data, 9, 68 (1964).Google Scholar
28. Block, J., and Gray, A. P., Inorganic Chem, 4, 305 (1965).Google Scholar