Cation Location in Dehydrated Na−Rb−Y Zeolite: An XRD and IR Study
| Autor: | A. Zecchina, G.L. Marra, M. Salvalaggio, Gabriele Ricchiardi, Carlo Lamberti, Silvia Bordiga, Andrew N. Fitch |
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| Rok vydání: | 1997 |
| Předmět: |
N2 adsorption
Chemistry Rietveld refinement structural detrmination zeolite cation location XRPD powder XRD Rietveld refinment FTIR CO adsorption cation discrimination Powder xrd Cell parameter Surfaces Coatings and Films chemistry.chemical_compound Crystallography Adsorption Materials Chemistry Physical and Theoretical Chemistry Zeolite Carbon monoxide |
| Zdroj: | The Journal of Physical Chemistry B. 101:10653-10660 |
| ISSN: | 1520-5207 1520-6106 |
| DOI: | 10.1021/jp971747n |
| Popis: | High-quality powder XRD data of a dehydrated Na−Rb−Y zeolite with Si/Al = 2.7, collected at the ESRF beam line BM16, are analyzed. The quality of the Rietveld refinement is very satisfactory, as confirmed by the low Rwp and Rp values of 7.77% and 6.02%, respectively, and by the comparison of the Rb+/Na+ ratio (1.36(6)) with the experimental one (1.38) obtained by analytical methods. We have found that 9.3(3) Na+ cations are located in site SI, 8.3(6) Na+ and 5.4(6) Rb+ cations in site SI‘, and 2.9(6) Na+ and 22.4(6) Rb+ cations in site SII. No cations have been observed in site SIII. Less than 4 cations out of 51.8 remain to be located in the unit cell, which has a cell parameter of a = 24.7673(4) A, (V = 15192.8(7) A3). The low occupancy by Na+ of sites in the supercage (site SII) is confirmed by a parallel IR study of CO and N2 adsorbed at low temperature, where carbon monoxide and dinitrogen have been found to interact mainly with the Rb+ cations. The spectroscopic study of the stretching vibrations of... |
| Databáze: | OpenAIRE |
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