Hamdan, Halimaton and Endud, Salasiah and He, Heyong and Mohd. Muhid, Mohd. Nazlan and Klinowski, Jacek (1996) Alumination of the purely siliceous mesoporous molecular sieve MCM-41 and its hydrothermal conversion into zeolite Na-A. Journal of the Chemical Society, Faraday Transactions, 92 (12). pp. 2311-2315. ISSN The Royal Society of Chemistry
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Official URL: htp://dx.doi.org/10.1039/FT9969202311
Purely siliceous mesoporous [Si]-MCM-41 has been aluminated using an aqueous solution of sodium aluminate, NaAlO2, to form [Si,Al]-MCM-41 with the framework Si/Al ratio as low as 1.9. 27Al and 29Si magic-angel-spinning (MAS) NMR show that all aluminium is incorporated in the framework. The well resolved X-ray diffraction (XRD) pattern of calcined [Si,Al]-MCM-41 indicates that the mesopore system is stable and that the channel diameter decreases with the increased degree of incorporation of Al. The intensity of lines corresponding to Si(nAl) building blocks in the 29Si MAS NMR spectra reflect changes in the local atomic arrangement upon alumination. Increased reaction temperature at a constant concentration of NaAlO2 enhances the efficiency of the alumination, but increased concentration at constant temperature disrupts the framework structure. Upon treatment with a concentrated (>1 mol 1–1) solution of NaAlO2 at moderate temperatures (100 ± 20 °C), [Si]-MCM-41 is transformed into crystalline zeolite Na-A.
|Uncontrolled Keywords:||mesoporous, MCM-41, zeolite Na-A|
|Subjects:||Q Science > QD Chemistry|
|Deposited By:||Kamariah Mohamed Jong|
|Deposited On:||04 Aug 2011 03:15|
|Last Modified:||28 Nov 2012 07:02|
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