Structure and Thermodynamics of the Mixed Alkali Alanates

Details Structure and Thermodynamics of the Mixed Alkali Alanates Structure and Thermodynamics of the Mixed Alkali Alanates

2005-01-21

arxiv.org/abs/cond-mat/0501536v2

Physics

Condensed Matter

Materials Science

6 pages, 7 figures,3 tables, submitted to PRB

Scientific paper

10.1103/PhysRevB.71.184115

The thermodynamics and structural properties of the hexahydride alanates (M2M'AlH6) with the elpasolite structure have been investigated. A series of mixed alkali alanates (Na2LiAlH6, K2LiAlH6 and K2NaAlH6) were synthesized and found to reversibly absorb and desorb hydrogen without the need for a catalyst. Pressure-composition isotherms were measured to investigate the thermodynamics of the absorption and desorption reactions with hydrogen. Isotherms for catalyzed (4 mol% TiCl3) and uncatalyzed Na2LiAlH6 exhibited an increase in kinetics, but no change in the bulk thermodynamics with the addition of a dopant. A structural analysis using synchrotron x-ray diffraction showed that these compounds favor the Fm-3m space group with the smaller ion (M') occupying an octahedral site. These results demonstrate that appropriate cation substitutions can be used to stabilize or destabilize the material and may provide an avenue to improving the unfavorable thermodynamics of a number of materials with promising gravimetric hydrogen densities.

Affiliated with

Also associated with

No associations

Rating

Structure and Thermodynamics of the Mixed Alkali Alanates does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Structure and Thermodynamics of the Mixed Alkali Alanates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structure and Thermodynamics of the Mixed Alkali Alanates will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-279570