Characterization of acid sites in dehydrated H-Beta zeolite by solid state NMR

摘要

A large panel of solid-state NMR techniques is used to characterize acid sites in steamed H-Beta. The structural environment of aluminum in hydrated H-Beta zeolite can be classically probed by ~(27)Al MAS NMR. In the case of dehydrated samples, structural information extracted from ~1H MAS and double resonance NMR experiments is used to propose a deconvolution of the ~(27)Al Hahn-Echo and QPASS spectra. This provides an estimation of the number and the geometry of aluminum sites.