Influence of doped rare earth elements on the dehydrogenation properties of VH2

Abstract

In this paper, using the plane waves ultrasoft pseudopotential method which is base on the first principles of DFT, we study the effects of C, Si, Ge, Sn and Pb alloying on the electronic structure and dehydrogenation properties of VH2. The calculated results show that the electron density of Ef fermi level is higher than that of pure VH2 alloy, exhibiting that the structural stability becomes weakened thus the hydrogen desorption property of VH2 can be improved. Moreover, the computed results of electron density of V-H bond also demonstrate that the interaction between V and H atoms decreases, also showing that the hydrogen desorption property of VH2 is improved. At the same time, it is found from the calculated results that the Mulliken population of V-s orbital increases whereas that of V-d orbital decreases, which is related to the enhanced dehydrogenation property alloyed by La, Ce and Pr.