Dehydrogenation properties and crystal structure analysis of Mg(BH 4)(NH2)

Tatsuo Noritake; Kazutoshi Miwa; Masakazu Aoki; Mitsuru Matsumoto; Shin Ichi Towata; Hai Wen Li; Shin Ichi Orimo

doi:10.1016/j.jallcom.2013.03.081

Dehydrogenation properties and crystal structure analysis of Mg(BH ₄)(NH₂)

Tatsuo Noritake, Kazutoshi Miwa, Masakazu Aoki, Mitsuru Matsumoto, Shin Ichi Towata, Hai Wen Li, Shin Ichi Orimo

Advanced Institute for Materials Research (AIMR)

Research output: Contribution to journal › Article › peer-review

15 Citations (Scopus)

Abstract

Dehydrogenation properties and crystal structure of the double anion complex hydride Mg(BH₄)(NH₂) were studied by thermal analyses and synchrotron X-ray diffraction. The stoichiometric mixture of Mg(BH₄)₂ and Mg(NH₂)₂ were ball-milled and then heated to 453 K to form Mg(BH₄)(NH₂) crystal. The dehydrogenation of Mg(BH₄)(NH₂) occurs in two-stage at 513 K and 688 K. The following reaction sequence is suggested by the results of thermal analyses; Mg(BH₄)(NH₂) → MgH₂ + BN + 2H₂ (7.3 mass% weight loss) → Mg + BN + 3H₂ (11.0 mass% weight loss in total). The dehydrogenation temperature of Mg(BH₄)(NH₂) is approximately 50 K lower than that of the other double anion complex Li₂(BH ₄)(NH₂). The crystal structure of Mg(BH ₄)(NH₂) was determined by the measurement at 300 K (crystal system: tetragonal, space group: I4₁ (No. 80), lattice constants: a = 5.792(1), c = 20.632(4) Å at 300 K). In the crystal of Mg(BH₄)(NH₂), the cation (Mg²⁺) and the anions (BH4- and NH2-) are stacked alternately along the c-axis direction. The Mg ²⁺ cation is tetrahedrally coordinated with two BH4- anions and two NH2- anions.

Original language	English
Pages (from-to)	S85-S89
Journal	Journal of Alloys and Compounds
Volume	580
Issue number	SUPPL1
DOIs	https://doi.org/10.1016/j.jallcom.2013.03.081
Publication status	Published - 2013

Keywords

Crystal structure
Hydrogen absorbing materials
Synchrotron radiation
X-ray diffraction

ASJC Scopus subject areas

Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

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10.1016/j.jallcom.2013.03.081

Cite this

@article{00bcb1d187184233aafdad235d5ebb3c,

title = "Dehydrogenation properties and crystal structure analysis of Mg(BH 4)(NH2)",

abstract = "Dehydrogenation properties and crystal structure of the double anion complex hydride Mg(BH4)(NH2) were studied by thermal analyses and synchrotron X-ray diffraction. The stoichiometric mixture of Mg(BH4)2 and Mg(NH2)2 were ball-milled and then heated to 453 K to form Mg(BH4)(NH2) crystal. The dehydrogenation of Mg(BH4)(NH2) occurs in two-stage at 513 K and 688 K. The following reaction sequence is suggested by the results of thermal analyses; Mg(BH4)(NH2) → MgH2 + BN + 2H2 (7.3 mass% weight loss) → Mg + BN + 3H2 (11.0 mass% weight loss in total). The dehydrogenation temperature of Mg(BH4)(NH2) is approximately 50 K lower than that of the other double anion complex Li2(BH 4)(NH2). The crystal structure of Mg(BH 4)(NH2) was determined by the measurement at 300 K (crystal system: tetragonal, space group: I41 (No. 80), lattice constants: a = 5.792(1), c = 20.632(4) {\AA} at 300 K). In the crystal of Mg(BH4)(NH2), the cation (Mg2+) and the anions (BH4- and NH2-) are stacked alternately along the c-axis direction. The Mg 2+ cation is tetrahedrally coordinated with two BH4- anions and two NH2- anions.",

keywords = "Crystal structure, Hydrogen absorbing materials, Synchrotron radiation, X-ray diffraction",

author = "Tatsuo Noritake and Kazutoshi Miwa and Masakazu Aoki and Mitsuru Matsumoto and Towata, {Shin Ichi} and Li, {Hai Wen} and Orimo, {Shin Ichi}",

note = "Funding Information: The authors express their heartfelt thanks to Dr. M. Fichtner (Forschungszentrum Karlsruhe) for Mg(BH 4 ) 2 sample provision. The synchrotron radiation experiments were carried out on BL19B2 of the SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No. 2009A1844). This work was partially supported by the New Energy and Industrial Technology Development Organization (NEDO), “Development for Hydrogen Production, Transportation and Storage System” Project. ",

year = "2013",

doi = "10.1016/j.jallcom.2013.03.081",

language = "English",

volume = "580",

pages = "S85--S89",

journal = "Journal of Alloys and Compounds",

issn = "0925-8388",

publisher = "Elsevier BV",

number = "SUPPL1",

}

TY - JOUR

T1 - Dehydrogenation properties and crystal structure analysis of Mg(BH 4)(NH2)

AU - Noritake, Tatsuo

AU - Miwa, Kazutoshi

AU - Aoki, Masakazu

AU - Matsumoto, Mitsuru

AU - Towata, Shin Ichi

AU - Li, Hai Wen

AU - Orimo, Shin Ichi

N1 - Funding Information: The authors express their heartfelt thanks to Dr. M. Fichtner (Forschungszentrum Karlsruhe) for Mg(BH 4 ) 2 sample provision. The synchrotron radiation experiments were carried out on BL19B2 of the SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No. 2009A1844). This work was partially supported by the New Energy and Industrial Technology Development Organization (NEDO), “Development for Hydrogen Production, Transportation and Storage System” Project.

PY - 2013

Y1 - 2013

N2 - Dehydrogenation properties and crystal structure of the double anion complex hydride Mg(BH4)(NH2) were studied by thermal analyses and synchrotron X-ray diffraction. The stoichiometric mixture of Mg(BH4)2 and Mg(NH2)2 were ball-milled and then heated to 453 K to form Mg(BH4)(NH2) crystal. The dehydrogenation of Mg(BH4)(NH2) occurs in two-stage at 513 K and 688 K. The following reaction sequence is suggested by the results of thermal analyses; Mg(BH4)(NH2) → MgH2 + BN + 2H2 (7.3 mass% weight loss) → Mg + BN + 3H2 (11.0 mass% weight loss in total). The dehydrogenation temperature of Mg(BH4)(NH2) is approximately 50 K lower than that of the other double anion complex Li2(BH 4)(NH2). The crystal structure of Mg(BH 4)(NH2) was determined by the measurement at 300 K (crystal system: tetragonal, space group: I41 (No. 80), lattice constants: a = 5.792(1), c = 20.632(4) Å at 300 K). In the crystal of Mg(BH4)(NH2), the cation (Mg2+) and the anions (BH4- and NH2-) are stacked alternately along the c-axis direction. The Mg 2+ cation is tetrahedrally coordinated with two BH4- anions and two NH2- anions.

AB - Dehydrogenation properties and crystal structure of the double anion complex hydride Mg(BH4)(NH2) were studied by thermal analyses and synchrotron X-ray diffraction. The stoichiometric mixture of Mg(BH4)2 and Mg(NH2)2 were ball-milled and then heated to 453 K to form Mg(BH4)(NH2) crystal. The dehydrogenation of Mg(BH4)(NH2) occurs in two-stage at 513 K and 688 K. The following reaction sequence is suggested by the results of thermal analyses; Mg(BH4)(NH2) → MgH2 + BN + 2H2 (7.3 mass% weight loss) → Mg + BN + 3H2 (11.0 mass% weight loss in total). The dehydrogenation temperature of Mg(BH4)(NH2) is approximately 50 K lower than that of the other double anion complex Li2(BH 4)(NH2). The crystal structure of Mg(BH 4)(NH2) was determined by the measurement at 300 K (crystal system: tetragonal, space group: I41 (No. 80), lattice constants: a = 5.792(1), c = 20.632(4) Å at 300 K). In the crystal of Mg(BH4)(NH2), the cation (Mg2+) and the anions (BH4- and NH2-) are stacked alternately along the c-axis direction. The Mg 2+ cation is tetrahedrally coordinated with two BH4- anions and two NH2- anions.

KW - Crystal structure

KW - Hydrogen absorbing materials

KW - Synchrotron radiation

KW - X-ray diffraction

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DO - 10.1016/j.jallcom.2013.03.081

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SN - 0925-8388

VL - 580

SP - S85-S89

JO - Journal of Alloys and Compounds

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