Characterization and quantification of aluminum species in zeolites using high-resolution 27Al solid state NMR
Résumé
27Al MAS and MQMAS NMR have been used to identify and quantify framework and extra-framework (EFAL) aluminum in Y zeolites stabilized by steaming and EFAL extraction using various leachings agents. It is useful to characterize contributions of different Al sites in USY. The decomposition of MAS and MQMAS was carried out with the use of a homemade software called MASAI. It takes benefits from the simultaneously analysis of a high resolved 2D-MQMAS and a quantitative MAS spectra. It allows a quantitative assignment of the framework and extra-framework aluminum species. Global and framework Si/Al ratios have been calculated by 27Al NMR and compared with Si/Al ratio found by X-Ray diffraction and X fluorescence.