合金化对VH_2解氢性能的影响  

Influence of Dopants on the Dehydrogenation Properties of VH_2

作　　者：李荣[1] 罗小玲[1] 梁国明[1] 付文升 

机构地区：[1]重庆师范大学化学学院,重庆400047

出　　处：《化学学报》2011年第11期1327-1336,共10页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20971132);重庆市自然科学基金(No.CSTC2009BB4243);重庆市教委科技项目(Nos.KJ090810;KJ070809)资助项目

摘　　要：采用密度泛函理论(DFT)的第一性原理的平面波超软赝势方法,研究了C,Si,Ge,Sn,Pb合金化对VH2的电子结构和解氢性能的影响.计算结果显示C,Si,Ge,Sn,Pb合金化VH2后晶体模型的负合金形成热减少,费米能级Ef处的电子浓度N(Ef)增加,表明体系结构稳定性减弱,解氢能力增强;V-H之间重叠集居数和电子密度计算也表明V-H之间相互作用减弱,解氢能力增强;同时Mulliken集居数计算结果还显示掺杂以后解氢能力增强与V-d轨道Mulliken集居数减少,V-s轨道Mulliken集居数增加有关.In this paper,using the plane waves ultrasoft pseudopotential method which base on the first principles of DFT,we have studied the effect of C,Si,Ge,Sn and Pb alloying on the electronic structure and dehydrogenation properties of VH2.The calculated results show that the generation heating of V-C,V-Si,V-Ge,V-Sn and V-Pb alloy are lower than those of pure VH2 alloy,and the electron density of Ef fermi level increases,exhibiting that the structural stability become weaken thus the hydrogen desorption property of VH2 can be improved.Moreover,the computed results of Mulliken populations and electron density of V-H bond also demonstrate that the interaction between V and H atom decrease,also exhibiting that the hydrogen desorption property of VH2 improve.At the same time,the calculated results find that the Mulliken popula-tion of V-s orbital increase whereas those of V-d orbital decrease,related to enhanced dehydrogenation property alloyed by C,Si,Ge,Sn and Pb.

关 键 词：元素掺杂 电子结构 解氢性能 第一原理计算 

分 类 号：TG139.7[一般工业技术—材料科学与工程]