Zeolite structural investigations by high resolution solid state MAS NMR

A number of techniques including single crystal and powder X-ray diffraction methods, IR, XPS, electron microscopy and neutron diffraction have been used to characterize zeolites. This paper discusses the adaptation of another method, solid state MAS NMR, for obtaining high resolution 29Si and 27Al spectra and thus establishing the local environments of these nuclei and how they are affected by sorbed molecules, temperature, defects and distortion. The ability to obtain high resolution spectra by the use of novel dealumination techniques has made it possible to identify atomic sites and together with X-ray data provides a more complete description of the structures of zeolites. (Auth.)