title: New amide-chloride phases in the Li-Al-N-H-Cl system: formation and hydrogen storage behaviour.
abstract: New amide-chloride phases were successfully synthesized by mechanical milling of the LiNH2-AlCl3 mixture at a molar ratio of 1 : 0.11 and further heating at 150 °C under argon (0.1 MPa) or under hydrogen pressure (0.7 MPa). Powder X-ray diffraction measurements as a function of milling time increase revealed that the milling of the LiNH2-0.11AlCl3 mixture results in the formation of a FCC solid solution with an excess of LiNH2. Subsequent heating of the LiNH2-0.11AlCl3 sample ball milled for 5 hours at 150 °C under argon or under hydrogen induces the appearance of an amide-chloride phase isostructural with cubic Li4(NH2)3Cl. This Li-Al-N-H-Cl phase transforms progressively into the trigonal phase after prolonged heating at 300 °C under hydrogen pressure. The thermal behaviour of the amide-chloride without and with LiH addition displays dissimilar decomposition pathways. The decomposition of amide-chloride alone involves the formation of ammonia and hydrogen from 120 to 300 °C. Conversely, the amide-chloride material in the presence of LiH only releases hydrogen avoiding the emission of ammonia. The resultant material is able to be rehydrogenated under moderate conditions (300 °C, 0.7 MPa H2), providing a new reversible hydrogen storage system.
authors.affiliation: Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro Atómico Bariloche (CNEA) and Instituto Balseiro (UNCu), Av. Bustillo 9500, R8402AGP Bariloche, Río Negro, Argentina. gennari@cab.cnea.gov.ar.
authors.forename: L
authors.initials: L
authors.lastname: Fernández Albanesi
authors.forename: S
authors.initials: S
authors.lastname: Garroni
authors.forename: S
authors.initials: S
authors.lastname: Enzo
authors.forename: F C
authors.initials: FC
authors.lastname: Gennari