A type of novel material with a high hy-drogen storage capacity was prepared by supporting PdNi18 alloy nanoparticles,which were synthesized by using a new colloid method,on the surface of pretreated multiwalled carbon nanotubes (MWCNTs). The average PdNi18 alloy particle sizes calculated from XRD patterns were ca. 3 nm,and the high dis-persion of these particles on MWCNTs was con-firmed by TEM image. Hydrogen storage perform-ance of the composite was investigated under mod-erate pressure (0.1―1.5 MPa) at room temperature,and a maximum storage capacity of ca. 2.3 wt% was achieved under 1.5 MPa at room temperature,which was much higher than that reported previously under the same conditions.
Two composites LaNi4.8Sn0.2/CNTs and NdNi4.8Sn0.2/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 MNi4.8Sn0.2 (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.
