Reactivity and acidity of Li in LiAlO[sub 2] phases
- Cornell Univ., Ithaca, NY (United States)
Nuclear physicists were interested in the [gamma]-modification of LiAlO[sub 2]. Because of its good performance under high neutron and electron radiation, the phase appears to be a promising lithium ceramic suitable as an in situ trituim-breeding material in future fusion reactors. With the help of semiempirical electronic structure calculations, the authors seek to understand why solid [alpha]-LiAlO[sub 2] exchanges Li[sup +] with H[sup +] while in contact with molten benzoic acid but [gamma]-LiAlO[sub 2] does not. After critically examining the structural data for LiAlO[sub 2] modifications, they calculate the binding and both the static and dynamic reactivity and the static and dynamic acidity of [alpha]- and [gamma]-LiAlO[sub 2], with a special interpretative emphasis on the Li ion. The reason for Li being solely extractable in [alpha]-LiAlO[sub 2] is found to arise from (1) a difference in Li electrophilicity between [alpha]- and [gamma]-phase (frontier band argument), (2) a significantly smaller energy for Li binding to its neighboring atoms in [alpha]-compared to [gamma]-phase (thermodynamic argument), and (3) a dramatic difference in energetic behavior upon dislocating a Li atom from its equilibrium position in [alpha]- and [gamma]-phase (kinetic argument). Additionally, the authors show how the movement of a local atomic carrier of reactivity and acidity within a nonequilibrium structure can be easily observed by use of computation. 64 refs., 12 figs., 3 tabs.
- OSTI ID:
- 6837438
- Journal Information:
- Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 32:1; ISSN 0020-1669; ISSN INOCAJ
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
DATA
ELECTRONIC STRUCTURE
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ACIDS
ION EXCHANGE
IONS
LEWIS ACIDS
LITHIUM COMPOUNDS
LITHIUM OXIDES
MATHEMATICAL MODELS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
THEORETICAL DATA