MNi4.8Sn0.2(M=La, Nd)-supported multi-walled carbon nanotube composites as hydrogen storage materials.

Two composites LaNi_4.8Sn_0.2/CNTs and NdNi_4.8Sn_0.2/CNTs were prepared by an impregnation-reduction method. Their hydrogen storage capacity could reach up to 2.96 wt% and 2.88 wt% respectively at room temperature and 1.0 MPa pressure. These values, which might result from the synergetic effect between the alloy nanoparticles and the pretreated CNTs, were three times higher than those of the unsupported MNi_4.8Sn_0.2(M=La, Nd) alloys under the same conditions. XRD and TEM revealed that the alloy particles were uniformly dispersed on the CNTs and the average particle size was Ca. 30 nm. The composites also showed good stability and the hydrogen storage capacity decreased by less than 6% after 100 adsorption-desorption cycles. Moreover, no noticeable change in crystalline structure was observed for the composites. [ABSTRACT FROM AUTHOR]