Rapid Microwave Synthesis, Characterization and Reactivity of Lithium Nitride Hydride, Li4NH

Materials

Nuria Tapia-Ruiz¹  Natalie Sorbie¹  Nicolas Vaché¹  Tuan K. A. Hoang¹ 

[1]WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK

[2] E-Mails:

关键词: nitride;    hydride;    structure;    microwaves;    synthesis;    hydrogen storage;    diffraction;    thermal analysis;    reactivity;   

DOI  :  10.3390/ma6115410

来源: mdpi

【 摘 要 】

Lithium nitride hydride, Li₄NH, was synthesised from lithium nitride and lithium hydride over minute timescales, using microwave synthesis methods in the solid state for the first time. The structure of the microwave-synthesised powders was confirmed by powder X-ray diffraction [tetragonal space group I4₁/a; a = 4.8864(1) Å, c = 9.9183(2) Å] and the nitride hydride reacts with moist air under ambient conditions to produce lithium hydroxide and subsequently lithium carbonate. Li₄NH undergoes no dehydrogenation or decomposition [under Ar_(g)] below 773 K. A tetragonal–cubic phase transition, however, occurs for the compound at ca. 770 K. The new high temperature (HT) phase adopts an anti-fluorite structure (space group Fmm; a = 4.9462(3) Å) with N³⁻ and H⁻ ions disordered on the 4a sites. Thermal treatment of Li₄NH under nitrogen yields a stoichiometric mixture of lithium nitride and lithium imide (Li₃N and Li₂NH respectively).

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.