Investigation of Ti-doped NaAlH4 by solid-state NMR
Abstract
In recent years, the development of Ti-doped NaAlH{sub 4} as a hydrogen storage material has gained attention because of its large weight percentage of hydrogen ({approx}5%) compared to traditional interstitial hydrides. The addition of transition-metal dopants, in the form of Ti-halides, such as TiCl{sub 3}, dramatically improves the kinetics of the absorption and desorption of hydrogen from NaAlH{sub 4}. However, the role that Ti plays in enhancing the absorption and desorption of H{sub 2} is still unknown. In the present study, {sup 27}Al, {sup 23}Na, and {sup 1}H MAS (Magic Angle Spinning) NMR (Nuclear Magnetic Resonance) has been performed to understand the titanium speciation in Ti-doped NaAlH{sub 4}. All experiments were performed on a sample of crushed single crystals exposed to Ti during growth, a sample of solvent-mixed 4TiCl{sub 3} + 112NaAlH{sub 4}, a reacted sample of solvent-mixed TiCl{sub 3} + {sup 3}NaAlH{sub 4} with THF, and a reacted sample of ball-milled TiCl3 + 3NaAlH{sub 4}. The {sup 27}Al MAS NMR has shown differences in compound formation between solvent-mixed TiCl{sub 3} + 3NaAlH{sub 4} with THF and the mechanically ball-milled TiCl{sub 3} + 3NaAlH{sub 4}. {sup 27}Al MAS NMR of the mechanically ball-milled mixture of fully-reacted TiCl{sub 3} + 3NaAlH{submore »
- Authors:
- Publication Date:
- Research Org.:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 15013709
- Report Number(s):
- UCRL-PROC-201208
TRN: US200803%%1079
- DOE Contract Number:
- W-7405-ENG-48
- Resource Type:
- Conference
- Resource Relation:
- Conference: Presented at: Material Research Society, Boston, MA, United States, Dec 01 - Dec 05, 2003
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; ABSORPTION; DESORPTION; HYDRIDES; HYDROGEN; HYDROGEN STORAGE; INTERSTITIALS; KINETICS; MAGNETIC RESONANCE; MIXTURES; MONOCRYSTALS; TITANIUM
Citation Formats
Maxwell, R, Majzoub, E, and Herberg, J. Investigation of Ti-doped NaAlH4 by solid-state NMR. United States: N. p., 2003.
Web.
Maxwell, R, Majzoub, E, & Herberg, J. Investigation of Ti-doped NaAlH4 by solid-state NMR. United States.
Maxwell, R, Majzoub, E, and Herberg, J. 2003.
"Investigation of Ti-doped NaAlH4 by solid-state NMR". United States. https://www.osti.gov/servlets/purl/15013709.
@article{osti_15013709,
title = {Investigation of Ti-doped NaAlH4 by solid-state NMR},
author = {Maxwell, R and Majzoub, E and Herberg, J},
abstractNote = {In recent years, the development of Ti-doped NaAlH{sub 4} as a hydrogen storage material has gained attention because of its large weight percentage of hydrogen ({approx}5%) compared to traditional interstitial hydrides. The addition of transition-metal dopants, in the form of Ti-halides, such as TiCl{sub 3}, dramatically improves the kinetics of the absorption and desorption of hydrogen from NaAlH{sub 4}. However, the role that Ti plays in enhancing the absorption and desorption of H{sub 2} is still unknown. In the present study, {sup 27}Al, {sup 23}Na, and {sup 1}H MAS (Magic Angle Spinning) NMR (Nuclear Magnetic Resonance) has been performed to understand the titanium speciation in Ti-doped NaAlH{sub 4}. All experiments were performed on a sample of crushed single crystals exposed to Ti during growth, a sample of solvent-mixed 4TiCl{sub 3} + 112NaAlH{sub 4}, a reacted sample of solvent-mixed TiCl{sub 3} + {sup 3}NaAlH{sub 4} with THF, and a reacted sample of ball-milled TiCl3 + 3NaAlH{sub 4}. The {sup 27}Al MAS NMR has shown differences in compound formation between solvent-mixed TiCl{sub 3} + 3NaAlH{sub 4} with THF and the mechanically ball-milled TiCl{sub 3} + 3NaAlH{sub 4}. {sup 27}Al MAS NMR of the mechanically ball-milled mixture of fully-reacted TiCl{sub 3} + 3NaAlH{sub 4} showed spectral signatures of TiAl{sub 3} while, the solvent-mixed 4TiCl{sub 3} + 112NaAlH{sub 4}, which is totally reacted, does not show the presences of TiAl{sub 3}, but shows the existence of Al{sub 2}O{sub 3}.},
doi = {},
url = {https://www.osti.gov/biblio/15013709},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Nov 24 00:00:00 EST 2003},
month = {Mon Nov 24 00:00:00 EST 2003}
}