properties of boranates funchy 2006 1st workshop of the … · 2008. 2. 12. · 4 4 andreas...

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1 Andreas Züttel, IfRES 27.01.2005

PROPERTIES OF BORANATES

ANDREAS ZÜTTEL

CONTENTS1) STABILITY2) KINETICS3) STRUCTURE OF LiBH44) MODEL5) FUTURE

EMPA Materials Sciences and TechnologyDept. Environment, Energy and MobilityAbt. Hydrogen & EnergyCH-8600 DübendorfSwitzerland

Solid State Physics of Energy Storage SystemsFaculty of SciencesDivision of Physics and AstronomyVRIJE UNIVERSITEIT AmsterdamThe Netherlands

Institute for Renewable Energy Switzerland (IfRES)Physics DepartmentUNIVERSITY of FRIBOURGSWITZERLAND

FuncHy 20061st Workshop of the Helmholtz InitiativeFunctional Materials formobile Hydrogen StorageGKSS Research Centre Geesthacht,September 20-22, 2006

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HYDROGEN DENSITY

Ref: A. Züttel, “Materials for hydrogen storage”, materialstoday, Septemper (2003), pp. 18-27

HcovH±

H2

3


COMPLEX HYDRIDES

( )0

00

S

HppTdecΔ

Δ==

+ -

Ref.: B. Bogdanovic et al., J. Alloys and Comp. 302 (2000), pp. 36-58

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FIRST SYNTHESIS OF LiBH4H. I. SCHLESINGER, HERBERT C. BROWN, “Metallo Borohydrides. III. Lithium Borohydride”, J. of the Americ. Chemi. Society 62 (1940), pp. 3429-3435

SCHLESINGER H I; BROWN H C; ABRAHAM B; BOND A C; DAVIDSON N; FINHOLT A E; GILBREATH J R; HOEKSTRA H; HORVITZ L;HYDE E K; KATZ J J; KNIGHT J; LAD R A; MAYFIELD D L; RAPP L; RITTER D M; SCHWARTZ A M; SHEFT I; TUCK L D; WALKER A O, “New Developments in the Chemistry of Diborane and the Borohydrides: I. General Summary”, J. Am. Chem. Soc. (1953), 75, pp. 186-190

H. I. SCHLESINGER, HERBERT C. BROWN, JAMES R. GILBREATH AND J. J. KATZ, “Reaction of the Boron Halides with the Alkali Metal Hydrides and with Their Addition Compounds; A New Synthesis of Diborane”, J. Am. Chem. Soc. (1953), 75, pp. 195-199

H. I. SCHLESINGER, HERBERT C. BROWN, HENRY R. HOEKSTRA AND LOUIS R. RAPP, “Reactions of Diborane with Alkali Metal Hydrides and Their Addition Compounds. New Syntheses of Borohydrides. Sodium and Potassium Borohydrides”, J. Am. Chem. Soc. (1953), 75, 199-204

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THERMAL DESORPTION OF H2 FROM OF LiBH4

Ref.: D. S. Stasinevich and G. A. Egorenko, Russian J. of Inorganic Chemistry 13(3) (1968), pp. 341-343

Polymorphic transformation

fusion

H2desorption

50% of H2desorption

1.5 mol H2LiH + B

I II III IV

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STABILITY OF LiBH4

Ref.: D. S. Stasinevich and G. A. Egorenko, Russian J. of Inorganic Chemistry 13(3) (1968), pp. 341-343

LiBH4 LiH + B + 3/2H2ΔH = -68.9 kJ mol-1 H2ΔS = 99.9 J·K-1mol-1 H2

MeasurementΔH = -177.4 kJ mol-1 H2ΔS = 238.7 J·K-1mol-1 H2

LiBH4 Li + B + 2H2ΔH = -97.0 kJ mol-1 H2ΔS = 109.7 J·K-1mol-1 H2

IIIIIIIV

823 K753 K

703 K

Ref.: S.-I. Orimo, Tohoku Uni. Japan (2005)

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THERMAL H2 DESORPTION FROM LiBH4

catalyzed

pure

into vacuum

Ref.: W. G. Brown, L. Kaplan, K. E. Wilzbach, J. Amer. Chem. Soc. 74 (1952), pp. 1343-1344

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ACTIVATION ENERGY FOR LiBH4 LiH + B + 3/2 H2

catalyzed

pure

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STRUCTURE OF LiBH4 AT 293K (20°C)

Orthorhombic symmetryspace group: Pnma (#62)a = 7.17858(4) Åb = 4.43686(2) Åc = 6.80321(4) ÅVol: 216.685 Å3, Z = 4

Atom x y zLi 0.1568 0.2500 0.1015 B 0.3040 0.25000 0.4305H1 0.900 0.25000 0.956 H2 0.404 0.25000 0.280 H3 0.172 0.054 0.428

Ref.: J-Ph. Soulié, G. Renaudin, R. Cerny, K. Yvon, J. Alloys and Comp. 346 (2002), pp. 200-205A. Züttel et al., Journal of Alloys and Compounds 356–357 (2003), pp. 515–520

SLS:GOZZO FabiaPATTERSON Bruce

Refinement:SHEPTYAKOV DenisFISCHER Peter

No single crystal exists!

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PHASETRANSITIONS LiBH4

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11 Andreas Züttel, IfRES 27.01.2005Andreas Züttel, Switzerland, 10/5/20061

STRUCTURE OF LiBH4 AT 408K (135°C)

hexagonal symmetryspace group: P63mc (#186)a = 4.27631(5) Åc = 6.94844(8) ÅVol: 110.041 Å3, Z = 2

Atom x y zLi 0.3333 0.6666 0.0000 B 0.3333 0.6666 0.553 H1 0.3333 0.6666 0.370 H2 0.172 0.344 0.624

Ref.: J-Ph. Soulié, G. Renaudin, R. Cerny, K. Yvon, J. Alloys and Comp. 346 (2002), pp. 200-205

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STABILITY OF LiBH4: DFT + PSEUDOPOTENTIAL

LiBH4 LiH + B + 3/2 H2Pnma phase

ΔH = 68.79 kJ·mol-1 H2Ref.: Terry Frankcombe, LIC / Theoretical Chemistry, University of Leiden, NL

ΔH = 68.90 kJ·mol-1 H2 @ 25°CRef.: Smith and Bass, J. Chem. Eng. Data 8 (1963), pp. 342

P63mc phase

ΔH = 54.08 kJ·mol-1 H2Ref.: Terry Frankcombe, LIC / Theoretical Chemistry, University of Leiden, NL

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13 Andreas Züttel, IfRES 27.01.2005Andreas Züttel, Switzerland, 10/5/20061

STRUCTURE PARAMETERS FOR LiBH4

Ref.: Zbigniew Lodziana and Tejs Vegge, "Structural stability of hydrides - LiBH4 revised", Physical Review Letters 93 (14): Art. No. 145501 (2004).

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INTERMEDIATE PHASES

Ref: Nobuko Ohba, Kazutoshi Miwa, Masakazu Aoki, Tatsuo Noritake, Shin-ichi Towata, Yuko Nakamori, Shin-ichi Orimo, and Andreas Züttel, “First-principles study on the stability of intermediate compounds of LiBH4”, Phys. Rev. B 74, 075110 (2006)

LiBH4 → LiH + B + 3/2 H2

LiBH4

Li, B, 2H2

LiH, B, 3/2 H2

ΔH

LiBH4

LiBH4

Li, B, 2 H2

PnmaP63mc

liq.

ΔHf0 -194.2 kJ

ΔHStruc4.4 kJ

ΔHm7.1 kJ

ΔH90.7 kJ

ΔH49.1 kJ

Li2B12H12, 5/6 LiH, 13/12 H2ΔH

42.9 kJ

ΔHf0 -97.1 kJ

ΔHStruc2.2 kJ

ΔHm3.6 kJ

ΔH45.3 kJ

ΔH181.5 kJ

ΔHf0 -182.7 kJ

ΔH103.0 kJ

ΔH60.6 kJ

ΔH56 kJ

“LiBH2”

“LiBH3.6”

“LiBH3”

LiH

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MECHANISM OF THE DECOMPOSITION (LiBH4)+

-+

-

+

-

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STABILITY OF BHn AND BHn-

Ref.: Puru Jena , Virginia Commonwealth University, Richmond, VA (to be published).

Gradient Corrected Density Functional Theory

Energy gain in adding a H atomBHn-1 + H → BHn

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STABILITY OF ABH4 AND AAlH4

0

0dec

SHT

Δ

Δ=

for p = p0

decomposition temperature

Ref.: Orimo S; Nakamori Y; Züttel A, “Material properties of MBH4 (M = Li, Na, and K)”, Materials Science and Engineering B108 (2004) , pp. 51–53

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Ref.: Y. Nakamori, K. Miwa, A. Ninomiya, H. Li, N. Ohba, S.-I. Towata, A. Züttel, and Shin-ichi Orimo, Physical Review B 74,

045126 (2006)

Electronegativitiy of M for MBH4

*

M + nB + 2nH2 → M(BH4)n

STABILITY OF M(BH4)x

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STABILITY OF BORANATES

Ref: Yuko Nakamori, Kazutoshi Miwa, Akihito Ninomiya, Haiwen Li, Nobuko Ohba, Shin-ichi Towata, Andreas Züttel, and Shin-ichi Orimo, “Correlation between thermodynamical stabilities of metal borohydrides and cation electronegativites: First-principles calculations and experiments”, Phys. Rev. B 74, 045126 (2006)

ΔH [kJ/mol BH4] = 248.7 χP – 390.8

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STRUCTURE OF Mg[BH4]2Mg[BH4]2 exists in two crystalline modifications:

α-Mg(BH4)2 has a tetragonal lattice (a = 13.59, c = 16.51 Å), while

β-Mg(BH4)2 has a cubic face-centered lattice (a = 15.5 Å).

The temperature of the polymorphic transition is 186°. The density of the-modification is 0.989 g/cm3.Ref.: V. N. Konoplev and V. M. Bakulina, “Some properties of magnesium borohydride”, Russian Chemical Bulletin 20:1 (1971), pp. 136-138

Mg[BH4]2 Max Fichtner, FZKprivate communications J.-C. Zhao, GE Global Research (IEA talk, March 2006)

0 302520151052θ angle (°)

Patte

rn N

umbe

r

0

5

10

15

20

25

30

35

Mg(BH4)2

Crystalline MgH2

Mg

295°C

380°C

Amorphous MgH2

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CHARGE DENSITY DISTRIBUTION

600

400

200

0

Inte

nsity

[Cou

nts]

6050403020102Θ [°]

30x103

20

10

0

Inte

nsity

[Cou

nts]

160140120100806040202Θ [°]

NEUTRON DIFFRACTION LiBD4

X-Ray DIFFRACTION LiBD4

Structure

Fullprof

Charge density maps

VASP, ElectrA

FT, MEM

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CHARGE DENSITY IN LiBH4 AT 293K (20°C)

Orthorhombic symmetry

Ref.: F. Buchter, A. Züttel, Ph. Mauron, A. Borgshulte, S.I. Towata, S.I. Orimo, “Determination of the electronic charge density from synchrotron X-ray diffraction and neutron diffraction for light complex hydrides”, Phys. Rev. B (2006), to be submitted

0

0 0

0

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REVERSIBILITY OF H2 SORPTION FROM LiBH4

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REVERSIBILITY OF LiBH4

Ref. A. Züttel et al., to be published

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SYNTHESIS OF LiBH4 FROM THE ELEMENTS

Li + B + 2H2 LiBH4p = 150 bar H2, T = 650°C

19581958

properties of boranates funchy 2006 1st workshop of the … · 2008. 2. 12. · 4 4 andreas...

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