کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1618538 1005707 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mechanochemically driven nonequilibrium processes in MNH2–CaH2 systems (M = Li or Na)
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
Mechanochemically driven nonequilibrium processes in MNH2–CaH2 systems (M = Li or Na)
چکیده انگلیسی

Mechanochemical transformations of lithium and sodium amides with calcium hydride have been investigated using gas volumetric analysis, X-ray powder diffraction, and residual gas analysis. The overall mechanochemical transformations are equimolar, and they proceed as the following solid state reaction: MNH2 + CaH2 → CaNH + MH + H2, where M = Li or Na. The transformation kinetics of the lithium containing system is markedly faster compared to the system with sodium. The difference in the rates of solid state transformations, and therefore, in hydrogen release kinetics can be explained by difference in mobility of lithium and sodium atoms. Total energies and enthalpies of formation for different reaction products during the dehydrogenation of CaH2–MNH2 mixtures were calculated using density functional theory. Compared to thermochemical transformations, which proceed in accordance with thermodynamic equilibrium, reactions induced by mechanical energy drive the MNH2–CaH2 systems to nonequilibrium configurations with different final products.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volume 506, Issue 1, 10 September 2010, Pages 224–230
نویسندگان
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