Characterization of delaminated zeolites by 129Xe NMR with laser-hyperpolarized xenon.
Résumé
Delaminated materials (ITQ-2 and ITQ-6) and their corresponding zeolite precursors, MCM-22 and ferrierite, resp., have been studied with 129Xe NMR of adsorbed xenon. With respect to the spectra of the precursors, one-dimensional (1D) spectra of delaminated materials show addnl. lines at lower chem. shift characteristic of larger adsorption sites. Two-dimensional (2D) exchange NMR expts. of samples under magic angle spinning conditions and continuous flow of Xe allowed to det. the exchange between different sites and obtain information on the delamination process.