In the work, the results of Al-27 MAS NMR studies carried out for structures of different framework aluminosilicates are presented. The spectra of natural clinoptilolite and its sodium and hydrogen forms were measured. The zeolite spectra were obtained before and after incorporation of heavy metal cations (Pb2+, Cd2+, Ni2+ and Cr3+) into the zeolite structure. After decomposition of the spectra into component peaks differences caused by ion exchange were observed.
Additionally, NMR spectra of kalsilite (framework aluminosilicate, not belonging to zeolite group) and other zeolites (chabazite, heulandite and analcime) were measured.
Al-27 MAS NMR spectra of all the samples studied were compared with the FTIR spectra measured in the middle infrared region.
Based on the results obtained it has been proved that the interpretation of spectra obtained using these two different techniques can give some information concerning changes occurring in various framework aluminosilicate structures.
(C) 2002 Elsevier Science B.V. All rights reserved.