Abstract
Accordingly, the observation of oxygen selectivity on Na-K-A would indicate that nitrogen has a greater steric hindrance at the window than does oxygen. Using single crystal X-ray diffraction (SCXD), it was confirmed that K at 8-member rings was relocated to 6-member rings and that the location of Na at 8-member rings became uncertain with calcination. It was also observed that Na-K-A was thermally more stable than Na-A. Using magic angle spin nuclear magnetic resonance (MAS-NMR), it was confirmed that Na at 8-member rings irreversibly changed location from a symmetric position to an asymmetric position with calcination.
Using the atomic positions determined by SCXD, the mean square displacements (MSD) of oxygen and nitrogen inside the crystal of Na-A and Na-K-A were estimated by means of molecular dynamic simulation (MD). When temperature was decreased, the MSD of nitrogen was reduced to a greater extent than that of oxygen and the MSD of nitrogen inside Na-K-A was reduced by a greater margin than that inside Na-A.
Similar content being viewed by others
References
Berlin, N.H. et al., US Patent 3282028, 1966.
Blackwell, C.S., J.J. Pluth, and J. Smith, Phys. Chem., 89, 4420–4422 (1985).
Breck, D.W. and J.V. Smith, Sci. Am., 280, 85 (1959).
Kawamura, K., I. Okada, and E. Osawa, Kaibundou, "Bunshi simyureishon nyuumon" (1989).
Izumi, J. and M. Suzuki, Adsorption, 6(1), 23–31 (2000).
Izumi, J. and M. Suzuki, Adsorption, submitted.
Izumi, J., A. Yasutake, N. Oka, N. Tomonaga, H. Ohta, N. Akutsu, M. Tajika, and S. Umeda, in Proceedings of the IZC95, Seoul, (1996).
Takaishi, T., Koubutu Gakukaishi, 17(3), 131–138 (1985).
Veeman, W.S. et al., J. Phys. Chem., 93, (2) (1989).
Yanagida, R.Y., A.A. Amaro, and K. Seff, J. Phys. Chem., 77, 805–809 (1973).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Oka, N., Izumi, J. & Suzuki, M. Mechanism of Oxygen Adsorption on Partially K Exchanged Na-A Type Zeolite. Adsorption 6, 149–158 (2000). https://doi.org/10.1023/A:1008917502054
Issue Date:
DOI: https://doi.org/10.1023/A:1008917502054