采用基于密度泛函理论的第一性原理方法,计算了LiAlH4-Cl体系的晶体与电子结构及稳定性能.计算生成焓发现,Cl-均可替代LiAlH4晶体结构中不同位置的H原子、[AlH4]单元体及占间隙位,其占位难易程度从易到难依次为:间隙位>H2位>H4位>H3位>H1位>[AlH4]单元体.H原子解离能的计算发现:在Cl-替代[AlH4]单元和占据间隙位时,LiAlH4体系的结构稳定性变差,对应体系的放氢能力提高.其中,Cl-占据间隙位时,其对应体系放氢能力最强.费米能级附近能隙ΔEH-L值变小,对应体系的结构稳定性降低,是提高LiAlH4体系放氢能力的根本原因.
Based on the first-principles density functional theory,the crystal of LiAlH4-Cl system and electro-nic structure and stable performance were calculated.It is found that Cl atom can replace H atoms in different posi-tions,[AlH4 ]and vacancy of the LiAlH4 crystal structure.The site preference of the ternary additions in LiAlH4 al-loy from easy to difficult is vacancy bits> H2 bits > H4 bits > H3 bits > H1 bits > [AlH4 ]bits.The dissociation energy of H atom show that:when Cl atom substituted [AlH4 ]and occupied vacancy,there were some changes on structural stability,and befit to improve the dehydrogenating properties of the system.The system had strongest hy-drogen release ability when Cl atoms occupied interstitial sites.Improve LiAlH4 system put the root cause of the hy-drogen capacity:Near the Fermi level energyΔEH-L gap value decreased,the structure stability of the corresponding system reduced.
参考文献
| [1] | Yindee Suttisawat;Pramoch Rangsunvigit;Boonyarach Kitiyanan;Nongnuj Muangsin;Santi Kulprathipanja.Catalytic effect of Zr and Hf on hydrogen desorption/absorption of NaAlH_4 and LiAlH_4[J].International journal of hydrogen energy,20079(9):1277-1285. |
| [2] | 张同环;周仕学;牛海丽;肖成柱;王乃飞.碳助磨制备纳米镁铝储氢合金的结构及储氢性能研究[J].材料工程,2015(3):48-53. |
| [3] | Gottapu, Sanyasinaidu;Padhi, Santanu Kumar;Krishna, Mamidipudi Ghanashyam;Muralidharan, Krishnamurthi.Poly(vinylpyrrolidone) stabilized aluminum nanoparticles obtained by the reaction of SiCl4 with LiAlH4[J].New Journal of Chemistry,20157(7):5203-5207. |
| [4] | Destabilization Of Lialh_4 By Nanocrystalline Mgh_2[J].International journal of hydrogen energy,20095(5):2333-2339. |
| [5] | Ping Wang;Xiang Dong Kang;Hui Ming Cheng.Improved Hydrogen Storage of TiF_3-Doped NaAIH_4[J].Chemphyschem: A European journal of chemical physics and physical chemistry,200512(12):2488-2491. |
| [6] | 袁江;周惦武;彭平;侯德政.LiNH_2-X（X=Mg,Al,Ti,Nb）体系解氢性能的第一原理计算[J].化学学报,2011(14):1715-1720. |
| [7] | Zhang, J.;Sun, L. Q.;Zhou, Y. C.;Peng, P..Dehydrogenation thermodynamics of magnesium hydride doped with transition metals: Experimental and theoretical studies[J].Computational Materials Science,2015:211-219. |
| [8] | 李闯;周惦武;彭平;万隆.LiBH_4-X（X=O,F和Cl）体系解氢性能的第一原理计算[J].化学学报,2012(1):71-77. |
| [9] | Mirna Resan;Michael D. Hampton;Janice K. Lomness;Darlene K. Slattery.Effects of various catalysts on hydrogen release and uptake characteristics of LiAlH_4[J].International journal of hydrogen energy,200513/14(13/14):1413-1416. |
| [10] | 袁江;宋新华;卢端敏;候德政.掺杂V对LiNH2解氢性能的第一原理计算[J].材料导报,2013(20):156-160. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%