Mechanochemical transformations in NaNH(2)-MgH(2) mixtures

TitleMechanochemical transformations in NaNH(2)-MgH(2) mixtures
Publication TypeJournal Article
Year of Publication2012
AuthorsSingh NK, Kobayashi T, Dolotko O, Wiench JW, Pruski M, Pecharsky VK
Journal TitleJournal of Alloys and Compounds
Volume513
Pages324-327
Date Published02
Type of ArticleArticle
ISBN Number0925-8388
Accession NumberWOS:000298156400058
Keywordsdesorption, diffraction, hydrogen storage, hydrogen storage-system, imides, li, linh2-mgh2, linh2/mgh2 mixture, Mechanochemical transformation, n-h system, solid-state nmr, solids, x-ray
Abstract

Mechanochemical transformations occurring during ball milling of sodium amide (NaNH(2)) with magnesium hydride (MgH(2)) taken in 2:3 and 2:1 molar ratios have been investigated using X-ray powder diffraction (XRD) and solid-state nuclear magnetic resonance (SSNMR) techniques. For the 2NaNH(2)-3MgH(2) system the mechanochemical reaction proceeds via the formation of MgNH as an intermediate, whereas magnesium nitride (Mg(3)N(2)), sodium hydride (NaH) and hydrogen (similar to 5 wt%) form as the final products. The overall solid state reaction for this system is 2NaNH(2) + 3MgH(2) -> Mg(3)N(2) + 2NaH + 4H(2). However, the mechanochemical transformation of the 2NaNH(2)-MgH(2) system proceeds through the reaction: 2NaNH(2) + MgH(2) -> Mg(NH(2))(2) + 2NaH, without any hydrogen release. Comparison of the mechanochemical transformations with the previously studied thermochemical transformations reveals that the two approaches lead to the same final products via different reaction pathways. (C) 2011 Elsevier B. V. All rights reserved.

Alternate JournalJ. Alloy. Compd.