Synergistic effects of Ce and Ni on hydrogen storage properties in Mg-based alloys

To address the kinetic limitations of Mg-based hydrogen storage materials, the synergistic effects of Ce and Ni on hydrogen storage kinetics of Mg-based alloys were investigated. Microstructural evolution studies reveal that the as-cast 18R-type long-period ordered stacking phase (LPSO) phase decomposes into MgH2 and CeH2.73 phases, with an average particle size of approximately 50 nm after initial hydrogen absorption. The Mg-10Ni-10Ce alloy demonstrates exceptional hydrogen storage kinetics. At 300 degrees C and 40 bar H2, Mg-10Ni-10Ce particles with a size range of 200-400 mu m can dehydrogenate up to 6.4 wt% within 10 min and rehydrogenate up to 5.9 wt% within 1 h. This performance significantly surpasses that of Mg-8Ni control samples with same particle size. Analysis reveals that the addition of Ni significantly enhances dehydrogenation kinetics, while CeH2.73 particles accelerate H2 dissociation and serve as nucleation sites for the MgH2 phase. This synergistic effect markedly improves the hydrogen storage kinetics of the Mg-Ni-Ce alloy.