National Technical Reports Library

The National Technical Information Service acquires, indexes, abstracts, and archives the largest collection of U.S. government-sponsored technical reports in existence. The NTRL offers online, free and open access to these authenticated government technical reports. Technical reports and documents in its repository may be available online for free either from the issuing federal agency, the U.S. Government Publishing Office’s Federal Digital System website, or through search engines.

Details

Metastability and Crystal Structure of the Bialkali Complex Metal Hydride NaK(BH4)2.

PB2012105271

Publication Date	2008
Personal Author	Seballos, L.; Zhang, J. Z.; Ronnebro, E.; Herberg, J. L.; Majzoub, E. H.
Page Count	19
Abstract	A new bialkali borohydride, NaK(BH4)2, was synthesized by mechanical milling of NaBH4 and KBH4 in a 1:1 ratio. The synthesis was conducted based on a prediction from a computational screening of hydrogen storage materials suggesting the potential stability of NaK(BH4)2. The new phase was characterized using X-ray diffraction, Raman scattering and magic angle spinning (MAS) nuclear magnetic resonance (NMR). The Raman measurements indicated B-H vibrations of the (BH4)- anion, while magnetic resonance chemical shifts in 23Na, and 39K MAS NMR spectra showed new chemical environments for Na and K resulting from the formation of the new bialkali phase. X-ray diffraction spectra indicated a new crystal structure with rhombohedral symmetry, most likely in the space group R3, distinct from the starting materials NaBH4, and KBH4. Although in-situ XRD measurements indicated the material to be metastable, decomposing to the starting materials NaBH4 and KBH4, the successful synthesis of NaK(BH4)2 demonstrates the ability of computational screening to predict candidates for hydrogen storage materials.
Keywords	Metastability Crystal structure Mechanical milling Hydrogen storage Stability Magic angle spinning(MAS) Nuclear magnetic resonance(NMR)
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Livermore National Lab., CA.
Document Type	Technical Report
NTIS Issue Number	201209

Metastability and Crystal Structure of the Bialkali Complex Metal Hydride NaK(BH4)2.

Metastability and Crystal Structure of the Bialkali Complex Metal Hydride NaK(BH4)2.
PB2012105271

Publication Date	2008
Personal Author	Seballos, L.; Zhang, J. Z.; Ronnebro, E.; Herberg, J. L.; Majzoub, E. H.
Page Count	19
Abstract	A new bialkali borohydride, NaK(BH4)2, was synthesized by mechanical milling of NaBH4 and KBH4 in a 1:1 ratio. The synthesis was conducted based on a prediction from a computational screening of hydrogen storage materials suggesting the potential stability of NaK(BH4)2. The new phase was characterized using X-ray diffraction, Raman scattering and magic angle spinning (MAS) nuclear magnetic resonance (NMR). The Raman measurements indicated B-H vibrations of the (BH4)- anion, while magnetic resonance chemical shifts in 23Na, and 39K MAS NMR spectra showed new chemical environments for Na and K resulting from the formation of the new bialkali phase. X-ray diffraction spectra indicated a new crystal structure with rhombohedral symmetry, most likely in the space group R3, distinct from the starting materials NaBH4, and KBH4. Although in-situ XRD measurements indicated the material to be metastable, decomposing to the starting materials NaBH4 and KBH4, the successful synthesis of NaK(BH4)2 demonstrates the ability of computational screening to predict candidates for hydrogen storage materials.
Keywords	Metastability Crystal structure Mechanical milling Hydrogen storage Stability Magic angle spinning(MAS) Nuclear magnetic resonance(NMR)
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Livermore National Lab., CA.
Document Type	Technical Report
NTIS Issue Number	201209