The effect of compositional changes on the structural and hydrogen storage properties of (La-Ce)Ni5 type intermetallics towards compounds suitable for metal hydride hydrogen compression.
Résumé
The present work has been aiming at the synthesis and study of a series of La1−xCexNi5 (x = 0, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8) alloys in an attempt to investigate possible alterations of the hydrogen absorption/desorption properties The alloys were prepared by induction melting of the constituent elements. The systematic characterization of all new compounds by means of XRD and hydrogen sorption measurements revealed the effect of the partial substitution of La with Ce on the crystal structure and the final hydrogen storage properties of the alloys. Extensive absorption/desorption experiments (Van't Hoff diagrams) have shown that such alloys can be used to build a metal hydride compressor (MHC), compressing H2 gas from 0.2 MPa to 4.2 MPa using cold (20 °C) and hot (80 °C) water.