Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1627802 | Journal of Alloys and Compounds | 2006 | 4 Pages |
Abstract
The mixed alanate K2NaAlH6 has been synthesised by ball-milling a mixture of KH and NaAlH4 and subsequent annealing at 150 °C under a stabilizing hydrogen pressure. It takes a cubic ordered perovskite-type structure (space group Fm3¯m, a = 8.118(1) Ã
) where the ideal octahedral AlH63â units form a cubic close-packed structure with K+ in all tetrahedral sites and Na+ in all octahedral sites. K2NaAlH6 with 1 mol% TiF3 decompose quickly and reversibly with a flat plateau. Pressure-composition isotherms have been measured at five temperatures in the range 280-325 °C. The decomposition enthalpy and entropy were determined to 98(2) kJ/mol H2 and 150(4) J/(K mol H2) from the van't Hoff equation.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
M.H. Sørby, H.W. Brinks, A. Fossdal, K. Thorshaug, B.C. Hauback,