标题:
新型储氢材料B-N-H化合物储氢性能的理论研究A Theoretical Research on B-N-H for Hydrogen Storage Properties
作者:
刘蓝琦, 赵亚芹, 何垚
关键字:
储氢, 第一性原理, 硼氮氢化合物, 电子结构, 态密度, 脱氢Hydrogen Storage; First-Principles; B-N-H Compound; Electronic Structure; Density of State;
Dehydrogenation
期刊名称:
《Advances in Condensed Matter Physics》, Vol.2 No.4, 2013-11-12
摘要:
本文采用基于密度泛函理论的平面波赝势方法，探究B-N-H储氢材料的储氢性能。首先从NH4BH4出发，陆续通过改变基团结构，由NH3BH3过渡到[BH4][BH2 (NH3)2]，先后从晶体结构、电子结构的角度进行详细分析，并分别计算三种结构的脱氢能量，综合对比，为最终实现脱氢能量的降低提供理论依据。研究发现：NH4BH4、NH3BH3和[BH4][BH2 (NH3)2]三者均是从BH4或BH3团簇内脱去H最容易，然而NH4BH4中BH4和NH4团簇局域性非常强，脱氢所需能量较高；NH3BH3中NH3和BH3之间已成键，团簇间相互作用增强，于是B与周围H之间的相互作用减弱，脱氢能量降低；进一步改变基团结构,从[BH4][BH2 (NH3)2]的结构来看,BH4局域性更弱，BH4基团与BH2 (NH3)2基团的原子间轨道交叠更明显，相互作用更强，致使BH4基团内部B与H之间相互作用继续降低，于是脱氢能量进一步降低。
The
properties of B-N-H hydrogen storage materials have been studied by using the
plane-wave pseudo- potential method based on the density functional theory. It
begins with NH4BH4,changing the group
structures though NH3BH3to[BH4][BH2(NH3)2], analyzing these
three kinds of crystals according to their crystal structures and elec- tronic
structures and calculating their dehydrogenation energy separately, which will
provide a good theoretical basis to de- crease the dehydrogenation energy. The
results show that it is all most easily to remove H from BH4 or BH3 cluster as for NH4BH4, NH3BH3and[BH4][BH2 (NH3)2], but the
dehydrogenation energy of NH4BH4 is much higher than others owing to its strong
localization between BH4 and NH4.In the case of NH3BH3,
there exists chemical bonds between NH3 and BH3 enhancing the influence between clusters and weakening the interaction between
B and N and then decreasing the dehydrogenation energy as a result. After
further changing the group structure, the localization of BH4 in [BH4][BH2 (NH3)2] seems much weaker
leading to a wonderful consequence to reduce the dehydrogenation energy.