Molecular modeling of zeolite structure. 1. Properties of the sodalite cage

Journal Article · Tue Dec 22 23:00:00 EST 1987 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00260a005· OSTI ID:7148458

Mabilia, M; Pearlstein, R A; Hopfinger, A J

Free-valence geometry molecular mechanics calculations were carried out on a sodalite cage. Energy minimizations were performed as a function of cage oxygen geometry, flexibility of the surface hydroxyl groups, Si:Al composition and bonding topology, and choice of force-field parameters. The major finding is that incorporation of Al atoms into the sodalite cage has little effect on the optimized molecular geometry, but plays a major role on structural stability. As the amount of Al increases, the stability of the sodalite cage also increases. For a fixed Si:Al composition, bonding topologies having localized high density groupings of Al atoms from more stable sodalite cages than those build from random or uniform distributions of Al atoms. Al atoms also increase the ionic character of the sodalite cage. Unique framework oxygen geometries which maximize the stability of a sodalite cage were identified. The optimized sodalite cage structures located on the surface of a zeolite were found to be virtually, the same as those within a zeolite framework. Mobile ion-binding calculations, using Na/sup +/ and K/sup +/, indicate that ion-binding strength is most dependent upon the geometry of the cage oxygens. Al atoms play a relatively minor role in ion-binding energetics and specificity.

• Research Organization: Intersoft Inc., Lake Forest, IL (USA)
• OSTI ID: 7148458
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 109:26; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALUMINIUM COMPOUNDS
BINDING ENERGY
CATALYSTS
CRYSTAL STRUCTURE
DATA
ENERGY
ENERGY LEVELS
EXCITED STATES
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MATHEMATICAL MODELS
MATHEMATICS
MINERALS
MOLECULAR STRUCTURE
NUMERICAL DATA
SILICON COMPOUNDS
THEORETICAL DATA
TOPOLOGY
VALENCE
VIBRATIONAL STATES
ZEOLITES