Structure And Hydrogen Storage Properties Of Alloy And Porous Materials

The multiphases La-Mg-Ni alloy and the porous hydrogen storage materials were studiedin this work. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanningelectron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used tocharacterize the microstructure and the elemental analysis of hydrogen storage material. Thehydriding/dehydriding and charging/discharging performance was tested by PCT andelectrochemical test, respectively.The main results are shown as following:1. The alloy was prepared by induction melted method under argon atomosphere. Then itwas heated1123K for3days. XRD, ICP and EDS results showed that La-Mg-Ni alloy hadPr5Co19-type, Ce5Co19-type，CaCu5-type and Ce2Ni7-type phase. The mass fraction of eachphase was45.7%,17.6%,30.6%and5.3%. Electrochemical properties and PCT tests showedthat the hydriding/dehydriding and charging/discharging cycle stability were obviouslyimproved for the annealed alloy.2. The porous LaNi5pellets were prepared using urea, oxalic acid and ammoniumbicarbonate as the template. XRD result showed that only LaNi5alloy existed. SEM and BETresults showed that the hole and tube were existed in the porous LaNi5pellets. PCT testsshowed that the hydrogen storage capacity was increased compared with LaNi5alloy.3. Ni@Mg was prepared by the displacement reaction. XRD, BET and SEM resultsshowed that the porous Ni@Mg formed. PCT tests showed that the hydriding/dehydridingcurve of Ni@Mg was different from other magnesium alloy. It was an obvious physicaladsorption curve.4. The hollow TiO2with high specific surface area was prepared using yeast as atemplate. XRD results showed that it was an anatase phase. FT-IR results showed that noorganic was existed. PCT tests showed that its hydrogen storage capacity was~0.65wt%, andit slightly increased with the increase of temperature due to the formation of OH-H bonds.