Hydrogen storage performance of the as-milled Y[sbnd]Mg[sbnd]Ni alloy catalyzed by CeO2

Abstract

The YMgNi-based YMg11Ni + 5 wt%CeO2 (named YMg11Ni5CeO2) alloys were prepared by using mechanical ball milling. The influences of CeO2 on the structure and gaseous hydrogen storage performance of YMg11Ni alloy were studied systematically. The structures of sample alloy were determined by X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM). The gaseous hydrogen storage performances were tested by using an automatically controlled Sieverts apparatus. The dehydrogenation performance was studied by thermogravimetry (TG) and differential scanning calorimetry (DSC). The hydrogen desorption activation energy was calculated by adopting Kissinger methods. The results show that adding CeO2 into YMg11Ni can lower the hydrogen storage thermodynamics slightly and increase the hydrogen absorption/desorption rate obviously. Moreover, the hydrogen desorption activation energy (Ede(k)) of the alloys is 91.53 kJ mol−1 for YMg11Ni alloy and 74.89 kJ mol−1 for YMg11Ni5CeO2 alloy, respectively. This is because the hydrogen desorption kinetic of the alloy is improved by adding catalyst CeO2.