A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH2 through adding Ti catalysts

doi:10.1088/1674-1056/19/4/048601

中国物理B ›› 2010, Vol. 19 ›› Issue (4): 48601-048601.doi: 10.1088/1674-1056/19/4/048601

A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH₂ through adding Ti catalysts

刘贵立¹, 张辉², 戚克振², 张国英², 肖明珠², 朱圣龙³

(1)College of Constructional Engineering, Shenyang University of Technology, Shenyang 110023, China; (2)College of Physics Science and Technology, Shenyang Normal University, Shenyang 110034, China; (3)State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang {\rm 110016, China

收稿日期:2009-04-28 修回日期:2009-09-26 出版日期:2010-04-15 发布日期:2010-04-15
基金资助:
Project supported by the National High Technology Research $\&$ Development of China (Grant No.~2009AA05Z105), the National Natural Science Foundation of China (Grant No.~50671069), the Science Research Program of the Education Bureau of Liaoning Province

A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH₂ through adding Ti catalysts

Zhang Hui(张辉)^a)†, Liu Gui-Li(刘贵立)^b), Qi Ke-Zhen(戚克振)^a), Zhang Guo-Ying(张国英)^a), Xiao Ming-Zhu(肖明珠)^a), and Zhu Sheng-Long(朱圣龙)^c)

^a College of Physics Science and Technology, Shenyang Normal University, Shenyang 110034, China; ^b College of Constructional Engineering, Shenyang University of Technology, Shenyang 110023, China; ^c State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China

Received:2009-04-28 Revised:2009-09-26 Online:2010-04-15 Published:2010-04-15
Supported by:
Project supported by the National High Technology Research $\&$ Development of China (Grant No.~2009AA05Z105), the National Natural Science Foundation of China (Grant No.~50671069), the Science Research Program of the Education Bureau of Liaoning Province

摘要/Abstract

摘要： Experiments on a ball milled mixture with a 1:1 molar ratio of LiNH₂ and LiH with a small amount (1~mol %) of Ti$^nano$, TiCl₃ and TiO$₂^nano$ have revealed a superior catalytic effect on Li--N--H hydrogen storage materials. In the x-ray diffraction profiles, no trace of Ti$^nano$, TiCl₃ and TiO$₂^nano$ was found in these doped composites, by which we deduced that Ti atoms enter LiNH₂ by partial element substitution. A first-principles plane-wave pseudopotential method based on density functional theory has been used to investigate the catalytic effects of Ti catalysts on the dehydrogenating properties of LiNH$₂$ system. The results show that Ti substitution can reduce the dehydrogenation reaction activation energy of LiNH₂ and improve the dehydrogenating properties of LiNH₂. Based on the analysis of the density of states and overlap populations for LiNH$₂$ before and after Ti substitution, it was found that the stability of the system of LiNH$₂$ is reduced, which originates from the increase of the valence electrons at the Fermi level ($E_F)$ and the decrease of the highest occupied molecular orbital (HOMO)--lowest unoccupied molecular orbital (LUMO) gap ($\Delta E_H-L)$ near $E_F. The catalytic effect of Ti on the dehydrogenating kinetics of LiNH$₂$ may be attributed to the reduction of average populations between N--H per unit bond length (nm$^{ - 1})$, which leads to the reduction of the chemical bond strength of N--H.

Abstract: Experiments on a ball milled mixture with a 1:1 molar ratio of LiNH₂ and LiH with a small amount (1 mol %) of Ti^nano, TiCl₃ and TiO₂^nano have revealed a superior catalytic effect on Li--N--H hydrogen storage materials. In the x-ray diffraction profiles, no trace of Ti^nano, TiCl₃ and TiO₂^nano was found in these doped composites, by which we deduced that Ti atoms enter LiNH₂ by partial element substitution. A first-principles plane-wave pseudopotential method based on density functional theory has been used to investigate the catalytic effects of Ti catalysts on the dehydrogenating properties of LiNH₂ system. The results show that Ti substitution can reduce the dehydrogenation reaction activation energy of LiNH₂ and improve the dehydrogenating properties of LiNH₂. Based on the analysis of the density of states and overlap populations for LiNH₂ before and after Ti substitution, it was found that the stability of the system of LiNH₂ is reduced, which originates from the increase of the valence electrons at the Fermi level (E_F) and the decrease of the highest occupied molecular orbital (HOMO)--lowest unoccupied molecular orbital (LUMO) gap ($\Delta E_{\rm H-L})$ near E_F. The catalytic effect of Ti on the dehydrogenating kinetics of LiNH₂ may be attributed to the reduction of average populations between N--H per unit bond length (nm$^{ - 1})$, which leads to the reduction of the chemical bond strength of N--H.

Key words: LiNH₂, first-principles calculation, dehydrogenating properties, Ti catalytic mechanism

中图分类号: (Surface and interface chemistry; heterogeneous catalysis at surfaces)

82.65.+r

84.60.-h (Direct energy conversion and storage) 71.20.Ps (Other inorganic compounds) 82.30.-b (Specific chemical reactions; reaction mechanisms)

张辉, 刘贵立, 戚克振, 张国英, 肖明珠, 朱圣龙. A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH₂ through adding Ti catalysts[J]. 中国物理B, 2010, 19(4): 48601-048601.

Zhang Hui(张辉), Liu Gui-Li(刘贵立), Qi Ke-Zhen(戚克振), Zhang Guo-Ying(张国英), Xiao Ming-Zhu(肖明珠), and Zhu Sheng-Long(朱圣龙). A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH₂ through adding Ti catalysts[J]. Chin. Phys. B, 2010, 19(4): 48601-048601.

参考文献 21

[1]	Chen P, Xiong Z T, Luo J Z, Lin J Y and Tan K L 2002 Nature 420 302
[2]	Orimo S, Nakamori Y, Kitahara G, Miwa K, Ohba N, Noritake T and Towata S 2004 Appl. Phys. A 79 1765
[3]	Nakamori Y and Orimo S 2004 J. Alloys Compd. 370 271
[4]	Nakamori Y and Orimo S 2004 Mater. Sci. Eng. B 108 48
[5]	Ichikawa T, Hanada N, Isob S, Leng H Y and Fujii H 2005 J. Alloys. Compd. 404 435
[6]	Ichikawa T, Isobe S, Hanada N and Fujii H 2004 J. Alloys. Compd. 365 271
[7]	Isob S, Ichikawa T and Hanada N 2005 J. Alloys Compd. 404 439
[8]	Zhou J J, Chen Y G, Wu G L, Zheng X, Fang Y C and Gao T 2009 Acta Phys. Sin. 58 4853 (in Chinese)
[9]	Chen Y H, Kang L, Zhang C R, Luo L C and Ma J 2008 Acta Phys. Sin. 57 4866 (in Chinese)
[10]	Chen Y H, Kang L, Zhang C R, Luo L C and Pu Z S 2008 Acta Phys. Sin. 57 4174 (in Chinese)
[11]	Song Y and Guo Z X 2006 Phys. Rev. B 74 195120
[12]	Ohoyama K, Nakamori Y, Orimo S and Yamada K 2005 J. Phys. Soc. Jpn. 74 483
[13]	Segall M D, Lindan P L D, Probert M J, Pickard C J, Hasinp P J, Clark S J and Payne M C 2002 J. Phys. Condens. Matter 14 2717
[14]	Marlo M and Milman V 2000 Phys. Rev. B 62 2899
[15]	Liu Z M, Cui T, Ma Y M, Liu B B and Zou G T 2007 Acta Phys. Sin. 56 8 (in Chinese)
[16]	Vanderbilt D 1990 Phys. Rev. B 41 7892
[17]	Franscis G P and Payne M C 1990 J. Phys. Condens. Matter 2 4395
[18]	Hammer B, Hansen L B and Norkov J K 1999 Phys. Rev. B 59 7413
[19]	Monkhorst H J and Pack J D 1976 Phys. Rev. B 13 5188
[20]	Imai Y, Mukaida M and Tsunoda T 2000 Intermetallics 8 381
[21]	Wang J, Wang G and Zhao J 2002 Phys. Rev. B 66 035418

A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH₂ through adding Ti catalysts

A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH₂ through adding Ti catalysts

PDF (PC)

赞

可视化

摘要/Abstract

引用本文

使用本文

参考文献 21

相关文章 15

Metrics

本文评价

推荐阅读 0

[1]	彭景, 邹温馨, 田锐, 李航, 刘新敏. Effects of dielectric decrement on surface potential in a mixed electrolyte solution[J]. 中国物理B, 2018, 27(12): 126801-126801.
[2]	张红光, 郭振江, 陈珊, 张博, 张现仁. Microdroplet targeting induced by substrate curvature[J]. 中国物理B, 2018, 27(9): 96801-096801.
[3]	朱勇, 许名权, 周武. High-resolution electron microscopy for heterogeneous catalysis research[J]. 中国物理B, 2018, 27(5): 56804-056804.
[4]	雷军辉, 王秀峰, 林建国. Tuning electronic properties of the S₂/graphene heterojunction by strains from density functional theory[J]. 中国物理B, 2017, 26(12): 127101-127101.
[5]	孙明烨, 郑友进, 张蕾, 赵立萍, 张冰. Carbon-nanodot-coverage-dependent photocatalytic performance of carbon nanodot/TiO₂ nanocomposites under visible light[J]. 中国物理B, 2017, 26(5): 58101-058101.
[6]	李超, 孙俊杰, 陈铎, 韩广兵, 于淑云, 康仕寿, 梅良模. Novel Fe₃O₄@SiO₂@Ag@Ni trepang-like nanocomposites: High-efficiency and magnetic recyclable catalysts for organic dye degradation[J]. 中国物理B, 2016, 25(8): 88201-088201.
[7]	薛建明, 郭鹏, 盛倩. Surface-charge-governed electrolyte transport in carbon nanotubes[J]. 中国物理B, 2015, 24(8): 86601-086601.
[8]	刘新敏, 杨刚, 李航, 田锐, 李睿, 丁武泉, 袁若. A theoretical exploration of the influencing factors for surface potential[J]. 中国物理B, 2015, 24(6): 68202-068202.
[9]	李萍剑, 程凯, 陈远富, 王泽高, 郝昕, 刘竞博, 贺加瑞, 张万里 . Low platinum loading PtNPs/graphene composite catalyst with high electrocatalytic activity for dye-sensitized solar cells[J]. 中国物理B, 2012, 21(11): 118101-118101.
[10]	李晓东, 林振权, 宋美霞, 柯见洪. Competing role of catalysis-coagulation and catalysis-fragmentation in kinetic aggregation behaviours[J]. 中国物理B, 2010, 19(12): 128201-128201.
[11]	杨宇. Influence of Pb adatom on adsorption of oxygen molecules on Pb(111) surface: a first-principles study[J]. 中国物理B, 2010, 19(10): 108201-108201.
[12]	曹博, 贾艳辉, 李公平, 陈熙萌. Atomic diffusion in annealed Cu/SiO₂/Si (100) system prepared by magnetron sputtering[J]. 中国物理B, 2010, 19(2): 26601-026601.
[13]	陆华, 沈电洪, 邓新发, 薛其坤, N. Froumin, M. Polak. STUDY OF THE Al/GRAPHITE INTERFACE[J]. 中国物理B, 2001, 10(9): 832-835.
[14]	傅石友, 郭余峰, 王明吉, 张鹏翔. STUDY OF HOMOGENEOUS ADSORPTION KINETICS OF CRYSTAL VIOLET[J]. 中国物理B, 1995, 4(10): 721-726.
[15]	谢建军, 蒋平, 张开明. A THEORETICAL MODEL FOR H₂ DISSOCIATIVE ADSORPTION ON Cu SURFACES[J]. 中国物理B, 1995, 4(9): 691-697.