From Exothermic to Endothermic Dehydrogenation - Interaction of Monoammoniate of Magnesium Amidoborane and Metal Hydrides

	From Exothermic to Endothermic Dehydrogenation - Interaction of Monoammoniate of Magnesium Amidoborane and Metal Hydrides
	Chua, Yong Shen 1; Li, Wen 1,2; Wu, Guotao 1; Xiong, Zhitao 1; Chen, Ping 1
刊名	chemistry of materials
	2012-09-25
卷号	24 期号:18 页码:3574-3581
关键词	hydrogen storage amidoborane endothermic dehydrogenation
英文摘要	metal amidoborane ammoniate such as mg-(nh2bh3)(2)center dot nh3 and ca(nh2bh3)(2)center dot nnh(3) with n = 1, 2, release nh3 predominantly and endothermically at low temperatures in an open-system. however, a strong exothermic reaction occurs when these ammoniates were dehydrogenated in a closed-system, where the adducted nh3 take part in the reaction. our approach in tailoring the thermodynamic properties of mg(nh2bh3)(2)center dot nh3, by replacing its adducted nh3 with amide was successful, yielding a composite consisting of bimetallic amidoborane and mg(nh2)(2). crystal structures of bimetallic amidoboranes, i.e., na2mg(nh2bh3)(4) and k2mg(nh2bh3)(4) were identified and solved. significant improvement in the dehydrogenation thermodynamic was observed in the composite system as compared to the pristine mg(nh2bh3)(2)center dot nh3, i.e., the dehydrogenation enthalpies were altered from an exothermic to an endothermic one. in addition, the detection of bimetallic amidoboranes in the composites urges detailed investigation on pristine bimetallic amidoborane, to which later we found that na2mg(nh2bh3)(4) also dehydrogenated endothermically at the identical temperature range (ca. 150-170 degrees c) with that of composite systems. similar activation barriers were observed in na2mg(nh2bh3)(4) and composite systems, suggesting that metal hydride mediation may be the internal barrier that dominates the kinetic barrier of the composite system. first-principles calculations also showed that the thermodynamic stability of metal amidoborane (mnh2bh3, mab) increases with decreasing pauling electronegativity of the metal. based on the calculated results, a reactant stabilization approach was proposed, which suggests that forming a stable reactant is an effective way of reducing the exothermicity of the dehydrogenation of metal amidoborane.
WOS标题词	science & technology ; physical sciences ; technology
类目[WOS]	chemistry, physical ; materials science, multidisciplinary
研究领域[WOS]	chemistry ; materials science
关键词[WOS]	hydrogen storage properties ; thermal-decomposition ; crystal-structure ; ammonia-borane ; lithium hydride ; release ; complexes ; alkali ; na ; amidotrihydroborate
收录类别	SCI
语种	英语
WOS记录号	WOS:000309041000010
公开日期	2015-11-17
内容类型	期刊论文
源URL	[http://159.226.238.44/handle/321008/143143]
专题	大连化学物理研究所_中国科学院大连化学物理研究所
作者单位	1.Dalian Inst Chem Phys, Dalian 116023, Peoples R China 2.Natl Univ Singapore, Dept Phys, Singapore 117542, Singapore
推荐引用方式 GB/T 7714	Chua, Yong Shen,Li, Wen,Wu, Guotao,et al. From Exothermic to Endothermic Dehydrogenation - Interaction of Monoammoniate of Magnesium Amidoborane and Metal Hydrides[J]. chemistry of materials,2012,24(18):3574-3581.
APA	Chua, Yong Shen,Li, Wen,Wu, Guotao,Xiong, Zhitao,&Chen, Ping.(2012).From Exothermic to Endothermic Dehydrogenation - Interaction of Monoammoniate of Magnesium Amidoborane and Metal Hydrides.chemistry of materials,24(18),3574-3581.
MLA	Chua, Yong Shen,et al."From Exothermic to Endothermic Dehydrogenation - Interaction of Monoammoniate of Magnesium Amidoborane and Metal Hydrides".chemistry of materials 24.18(2012):3574-3581.