XRD and NMR investigation of Ti-compound formation in solution-doping of sodium aluminum hydrides: Solubility of Ti in NaAlH4 crystals grown in THF

E. H. Majzoub; J. L. Herberg; R. Stumpf; S. Spangler; R. S. Maxwell

doi:10.1016/j.jallcom.2004.10.056

XRD and NMR investigation of Ti-compound formation in solution-doping of sodium aluminum hydrides: Solubility of Ti in NaAlH₄ crystals grown in THF

E. H. Majzoub
, J. L. Herberg
, R. Stumpf
, S. Spangler
, R. S. Maxwell

Energy & Environmental Science & Technology

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

59 Scopus citations

Abstract

Sodium aluminum hydrides have gained attention due to their high hydrogen weight percent (5.5% ideal) compared to interstitial hydrides, and as a model for hydrides with even higher hydrogen weight fraction. The purpose of this paper is to investigate the Ti-compounds that are formed under solution-doping techniques, such as wet doping in solvents such as tetrahydrofuran (THF). Compound formation in Ti-doped sodium aluminum hydrides is investigated using X-ray diffraction (XRD) and magic angle spinning (MAS) nuclear magnetic resonance (NMR). We present lattice parameter measurements of crushed single crystals, which were exposed to Ti during growth. Rietveld refinements indicate no lattice parameter change and thus no solubility for Ti in NaAlH₄ by this method of exposure. In addition, X-ray diffraction data indicate that no Ti substitutes in NaH, the final decomposition product for the alanate. Reaction products of completely reacted (33.3 at.%-doped) samples that were solvent-mixed or mechanically milled are investigated. Formation of TiAl ₃ is observed in mechanically milled materials, but not solution mixed samples, where bonding to THF likely stabilizes Ti-based nano-clusters. The Ti in these clusters is activated by mechanical milling.

Original language	English
Pages (from-to)	265-270
Number of pages	6
Journal	Journal of Alloys and Compounds
Volume	394
Issue number	1-2
DOIs	https://doi.org/10.1016/j.jallcom.2004.10.056
State	Published - May 17 2005

Keywords

Hydrogen storage materials
Mechanical alloying
Neutron diffraction
Nuclear magnetic resonance
Rietveld refinement
Structural modeling
X-ray diffraction

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10.1016/j.jallcom.2004.10.056

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@article{5a62e879c5db4d12988a7baf4522dcfa,

title = "XRD and NMR investigation of Ti-compound formation in solution-doping of sodium aluminum hydrides: Solubility of Ti in NaAlH4 crystals grown in THF",

abstract = "Sodium aluminum hydrides have gained attention due to their high hydrogen weight percent (5.5\% ideal) compared to interstitial hydrides, and as a model for hydrides with even higher hydrogen weight fraction. The purpose of this paper is to investigate the Ti-compounds that are formed under solution-doping techniques, such as wet doping in solvents such as tetrahydrofuran (THF). Compound formation in Ti-doped sodium aluminum hydrides is investigated using X-ray diffraction (XRD) and magic angle spinning (MAS) nuclear magnetic resonance (NMR). We present lattice parameter measurements of crushed single crystals, which were exposed to Ti during growth. Rietveld refinements indicate no lattice parameter change and thus no solubility for Ti in NaAlH4 by this method of exposure. In addition, X-ray diffraction data indicate that no Ti substitutes in NaH, the final decomposition product for the alanate. Reaction products of completely reacted (33.3 at.\%-doped) samples that were solvent-mixed or mechanically milled are investigated. Formation of TiAl 3 is observed in mechanically milled materials, but not solution mixed samples, where bonding to THF likely stabilizes Ti-based nano-clusters. The Ti in these clusters is activated by mechanical milling.",

keywords = "Hydrogen storage materials, Mechanical alloying, Neutron diffraction, Nuclear magnetic resonance, Rietveld refinement, Structural modeling, X-ray diffraction",

author = "Majzoub, \{E. H.\} and Herberg, \{J. L.\} and R. Stumpf and S. Spangler and Maxwell, \{R. S.\}",

note = "Funding Information: This work was funded by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, in the Hydrogen, Fuel Cells \& Infrastructure Technologies Program under contract No. DE-AC36-83CH10093, and Sandia National Laboratories through the Laboratory Directed Research and Development program. NMR work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48. The authors thank V. Ozolins for useful discussions and Ken Stewart for construction of the hydrogen sorption apparatus.",

year = "2005",

month = may,

day = "17",

doi = "10.1016/j.jallcom.2004.10.056",

language = "English",

volume = "394",

pages = "265--270",

journal = "Journal of Alloys and Compounds",

issn = "0925-8388",

publisher = "Elsevier B.V.",

number = "1-2",

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TY - JOUR

T1 - XRD and NMR investigation of Ti-compound formation in solution-doping of sodium aluminum hydrides

T2 - Solubility of Ti in NaAlH4 crystals grown in THF

AU - Majzoub, E. H.

AU - Herberg, J. L.

AU - Stumpf, R.

AU - Spangler, S.

AU - Maxwell, R. S.

N1 - Funding Information: This work was funded by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, in the Hydrogen, Fuel Cells & Infrastructure Technologies Program under contract No. DE-AC36-83CH10093, and Sandia National Laboratories through the Laboratory Directed Research and Development program. NMR work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48. The authors thank V. Ozolins for useful discussions and Ken Stewart for construction of the hydrogen sorption apparatus.

PY - 2005/5/17

Y1 - 2005/5/17

N2 - Sodium aluminum hydrides have gained attention due to their high hydrogen weight percent (5.5% ideal) compared to interstitial hydrides, and as a model for hydrides with even higher hydrogen weight fraction. The purpose of this paper is to investigate the Ti-compounds that are formed under solution-doping techniques, such as wet doping in solvents such as tetrahydrofuran (THF). Compound formation in Ti-doped sodium aluminum hydrides is investigated using X-ray diffraction (XRD) and magic angle spinning (MAS) nuclear magnetic resonance (NMR). We present lattice parameter measurements of crushed single crystals, which were exposed to Ti during growth. Rietveld refinements indicate no lattice parameter change and thus no solubility for Ti in NaAlH4 by this method of exposure. In addition, X-ray diffraction data indicate that no Ti substitutes in NaH, the final decomposition product for the alanate. Reaction products of completely reacted (33.3 at.%-doped) samples that were solvent-mixed or mechanically milled are investigated. Formation of TiAl 3 is observed in mechanically milled materials, but not solution mixed samples, where bonding to THF likely stabilizes Ti-based nano-clusters. The Ti in these clusters is activated by mechanical milling.

AB - Sodium aluminum hydrides have gained attention due to their high hydrogen weight percent (5.5% ideal) compared to interstitial hydrides, and as a model for hydrides with even higher hydrogen weight fraction. The purpose of this paper is to investigate the Ti-compounds that are formed under solution-doping techniques, such as wet doping in solvents such as tetrahydrofuran (THF). Compound formation in Ti-doped sodium aluminum hydrides is investigated using X-ray diffraction (XRD) and magic angle spinning (MAS) nuclear magnetic resonance (NMR). We present lattice parameter measurements of crushed single crystals, which were exposed to Ti during growth. Rietveld refinements indicate no lattice parameter change and thus no solubility for Ti in NaAlH4 by this method of exposure. In addition, X-ray diffraction data indicate that no Ti substitutes in NaH, the final decomposition product for the alanate. Reaction products of completely reacted (33.3 at.%-doped) samples that were solvent-mixed or mechanically milled are investigated. Formation of TiAl 3 is observed in mechanically milled materials, but not solution mixed samples, where bonding to THF likely stabilizes Ti-based nano-clusters. The Ti in these clusters is activated by mechanical milling.

KW - Hydrogen storage materials

KW - Mechanical alloying

KW - Neutron diffraction

KW - Nuclear magnetic resonance

KW - Rietveld refinement

KW - Structural modeling

KW - X-ray diffraction

UR - https://www.scopus.com/pages/publications/17644374144

U2 - 10.1016/j.jallcom.2004.10.056

DO - 10.1016/j.jallcom.2004.10.056

M3 - Article

AN - SCOPUS:17644374144

SN - 0925-8388

VL - 394

SP - 265

EP - 270

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

IS - 1-2

ER -

XRD and NMR investigation of Ti-compound formation in solution-doping of sodium aluminum hydrides: Solubility of Ti in NaAlH₄ crystals grown in THF

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