To improve the hydrogen storage properties of Mg-based alloys, a composite material of MgH_2 + 10wt%LaH_3 + 10wt%NbH was prepared by a mechanical milling method. The composite exhibited favorable hydrogen desorption p...To improve the hydrogen storage properties of Mg-based alloys, a composite material of MgH_2 + 10wt%LaH_3 + 10wt%NbH was prepared by a mechanical milling method. The composite exhibited favorable hydrogen desorption properties, releasing 0.67wt% H2 within 20 min at 548 K, which was ascribed to the co-catalytic effect of LaH_3 and NbH upon dehydriding of MgH_2. By contrast, pure MgH_2, an MgH_2 + 20wt%LaH_3 composite, and an MgH_2 + 20wt%NbH composite only released 0.1wt%, 0.28wt%, and 0.57wt% H2, respectively, under the same conditions. Analyses by X-ray diffraction and scanning electron microscopy showed that the composite particle size was small. Energy-dispersive X-ray spectroscopic mapping demonstrated that La and Nb were distributed homogeneously in the matrix. Differential thermal analysis revealed that the dehydriding peak temperature of the MgH_2 + 10wt%LaH_3 + 10wt%NbH composite was 595.03 K, which was 94.26 K lower than that of pure MgH_2. The introduction of LaH_3 and NbH was beneficial to the hydrogen storage performance of MgH_2.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 50971112 and 51471065)the Scientific Research Projects in Colleges and Universities in Hebei Province, China (ZD2014004)
文摘To improve the hydrogen storage properties of Mg-based alloys, a composite material of MgH_2 + 10wt%LaH_3 + 10wt%NbH was prepared by a mechanical milling method. The composite exhibited favorable hydrogen desorption properties, releasing 0.67wt% H2 within 20 min at 548 K, which was ascribed to the co-catalytic effect of LaH_3 and NbH upon dehydriding of MgH_2. By contrast, pure MgH_2, an MgH_2 + 20wt%LaH_3 composite, and an MgH_2 + 20wt%NbH composite only released 0.1wt%, 0.28wt%, and 0.57wt% H2, respectively, under the same conditions. Analyses by X-ray diffraction and scanning electron microscopy showed that the composite particle size was small. Energy-dispersive X-ray spectroscopic mapping demonstrated that La and Nb were distributed homogeneously in the matrix. Differential thermal analysis revealed that the dehydriding peak temperature of the MgH_2 + 10wt%LaH_3 + 10wt%NbH composite was 595.03 K, which was 94.26 K lower than that of pure MgH_2. The introduction of LaH_3 and NbH was beneficial to the hydrogen storage performance of MgH_2.
