Recently, zeolites have been proposed as media for hydrogen by means of molecular adsorption. The interaction of a dihydrogen molecule on alkali metal ions in high-silica zeolites has been theoretically studied in cluster and periodic models at the B3-LYP level of theory. The cluster models have been obtained by embedding Li+, Na+, and K+ in aluminosilicate rings of different sizes (Sin-1AlOnH2n, 4 <= n <= 6). The structure of Li, Na, and K-exchanged chabazite with Si/Al = 11:1 has been adopted as the periodic model. In both cases, the hydrogen molecule interacts side-on with the cations, forming T-shaped complexes. The results have been compared with similar data obtained for bare cations and previous experimental studies. Furthermore, the necessity of employing correlated methods for a proper description of the interaction has been verified at the MP2 level.

Interaction of H2 with Alkali-Metal-Exchanged Zeolites: a Quantum Mechanical Study

J.G. VITILLO;A. ZECCHINA
2007-01-01

Abstract

Recently, zeolites have been proposed as media for hydrogen by means of molecular adsorption. The interaction of a dihydrogen molecule on alkali metal ions in high-silica zeolites has been theoretically studied in cluster and periodic models at the B3-LYP level of theory. The cluster models have been obtained by embedding Li+, Na+, and K+ in aluminosilicate rings of different sizes (Sin-1AlOnH2n, 4 <= n <= 6). The structure of Li, Na, and K-exchanged chabazite with Si/Al = 11:1 has been adopted as the periodic model. In both cases, the hydrogen molecule interacts side-on with the cations, forming T-shaped complexes. The results have been compared with similar data obtained for bare cations and previous experimental studies. Furthermore, the necessity of employing correlated methods for a proper description of the interaction has been verified at the MP2 level.
2007
http://pubs.acs.org/cgi-bin/abstract.cgi/jpccck/2007/111/i06/abs/jp0673765.html
GAUSSIAN-BASIS SETS; MOLECULAR-HYDROGEN ISOTOPES; OXYGEN-BRIDGED SILICON; WAVE-FUNCTIONS; EQUILIBRIUM GEOMETRIES; ALUMINUM ATOMS; CO ADSORPTION; DENSITY; CHABAZITE; STORAGE
Torres, F. J.; Vitillo, J. G.; Civalleri, B.; Ricchiardi, G.; Zecchina, A.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11383/2076388
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