Variable temperature high resolution 29Si MAS NMR of siliceous zeolite ferrierite

Abstract

Variable temperature high resolution magic angle spinning ²⁹Si NMR spectroscopy is used to study the phase transition between the low and high temperature versions of pure silica ferrierite. Spectra collected at 133–400 K indicate that the low temperature phase is probably of lower symmetry than that previously reported using single crystal X-ray diffraction results. The NMR spectra around the phase transition are consistent with the description of the high temperature phase as a dynamic average of possible low temperature structures. A comparison of the NMR chemical shifts with the results of previous X-ray diffraction experiments confirms the validity of proposed correlations and indicates how they can be of predictive value in certain cases.