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

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 1 H 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.