Theoretical study of the site selectivity of zeolitic cations. Part 5 Site selectivities of transition metal ions in fully dehydrated zeolite A
✍ Scribed by Kiyoshi Ogawa; Masahiro Nitta; Kazuo Aomura
- Publisher
- Elsevier Science
- Year
- 1981
- Tongue
- English
- Weight
- 581 KB
- Volume
- 1
- Category
- Article
- ISSN
- 0144-2449
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✦ Synopsis
A theoretical interpretation is given for the site selectivities of Mn 2+, Fe 2+, Co 2+, Ni 2+, Zn 2+, Cd 2+, and Hg 2+ ions in fully dehydrated zeolite A. This zeolite was first envisioned as being either completely ionic or completely covalent in character. This cation-lattice interaction energies, consisting of electrostatic, polarization, dispersion, repulsion, crystal field, and charge transfer stabilization terms, were then calculated for cations occupying the sixand eight-membered oxygen ring sites in a simplified model of this zeolite structure. Finally, the completely ionic and completely covalent models were integrated to give realistic values for the cation-lattice interaction energies. The results of these calculations show that the first five incoming divalent cations prefer the six-membered oxygen ring sites whereas the sixth prefers an eight-membered site.