title: The mechanism of controllable dehydrogenation: CPMD study of M(BH4)x(NH3)y (M = Li, Mg) decomposition.
abstract: Amine metallic borohydrides were synthesized as a new series of hydrogen-storage materials. Their dehydrogenation can be controlled if appropriate metal centres are chosen. A typical example is LiBH4NH3 (ALB) and Mg(BH4)2(NH3)2 (AMgB) adopt the same symmetries but show totally different appearances when decomposed. Both ALB and AMgB are relatively new compounds designed as candidates for solid-state hydrogen storage. In this study, we have applied a Car-Parrinello molecular dynamic (CPMD) method to simulate the overall processes of their decomposition to figure out the mechanisms behind the difference in post-decomposition appearances. The polarization of Mg(2+) is almost two times larger than that of Li(+), making the Mg(2+) bond with nitrogen and boron stronger compared to that of Li(+), which improves the appearance of dehydrogenation of AMgB over that of ALB.
authors.affiliation: Department of Chemistry, Anhui University, Hefei, Anhui 230601, P. R. China. wangkun@ahu.edu.cn and Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, OX1 3QR, UK.
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, P. R. China. zjgbit@bit.edu.cn.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Zhang
authors.affiliation: State Key Lab of Mechatronics Engineering and Control, Beijing Institute of Technology, Beijing 100081, P. R. China. langxuqiang0536@163.com.
authors.forename: Xu-Qiang
authors.initials: XQ
authors.lastname: Lang