ISSN:
1573-1111
Keywords:
Magic angle spinning29Si NMR
;
magic angle spinning27Al NMR
;
sodium mordenite
;
zeolites
;
22736
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Magic angle spinning29Si NMR presents a rapid qualitative method of assessing the degree of dealumination of sodium mordenite modified by acid leaching and heat treatment. A quantitative determination of the29Si coordination sphere is hampered by the overlap of chemical shift ranges for Si−O−Al and Si−O−H species. MAS27Al NMR indicates the presence of octahedrally coordinated Al in interstitial sites in all treated samples. On treating mordenite samples at high temperatures (∼700°C) much of the Al becomes invisible to the NMR experiment because of its location in sites of low symmetry and large quadrupole coupling constant.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00656822
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