Published May 2007 | Version v1
Journal article

Mechanochemical transformations in Li(Na)AlH4-Li(Na)NH2 systems

  • 1. Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States)
  • 2. Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States)
  • 3. Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States) and Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States)

Description

Mechanochemical transformations of tetrahydroaluminates and amides of lithium and sodium have been investigated using gas volumetric analysis, X-ray powder diffraction, solid-state nuclear magnetic resonance (NMR) and transmission electron microscopy. In a transformation of LiAlH4 and LiNH2 taken in an 1:1 molar ratio, the amount of released hydrogen (6.6 wt.% after 30 min ball milling) was higher than in any known one pot mechanochemical process involving a hydrogen-containing solid. A total of 4.3 wt.% of hydrogen is released by the NaAlH4-NaNH2 system after 60 min ball milling; and 5.2 wt.% H2 is released when LiAlH4 and NaNH2 or NaAlH4 and LiNH2 are ball milled for 90 min and 120 min, respectively. All transformations proceed at room temperature. The mechanism of the overall transformation MAlH4(s) + MNH2(s) → 2MH(s) + AlN(s) + 2H2(g) was identified based on detailed spectroscopic analysis of the intermediate (M3AlH6) and final products of the ball milling process

Additional details

Identifiers

DOI
10.1016/j.actamat.2007.01.016;
PII
S1359-6454(07)00069-9;

Publishing Information

Journal Title
Acta Materialia
Journal Volume
55
Journal Issue
9
Journal Page Range
p. 3121-3130
ISSN
1359-6454
CODEN
ACMAFD

Optional Information

Copyright
Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.