One- and two-dimensional variable-temperature 13C MAS NMR studies on the adsorption of methane on zeolite HY

We present a C-13 MAS NMR Study On the adsorption of methane on KY zeolite. These investigations were carried out at temperatures ranging from 295 K to 135 K and at loadings up to 105 methane molecules per unit cell. Up to three signals appear in the C-13 MAS NMR spectra. From the dependence of their intensities and chemical shifts and results of H-1 PFG NMR measurements of diffusion it could be concluded that they are due to gaseous methane in the void space above the zeolite powder, to methane adsorbed in the large cavities of the HY zeolite and to methane in the pores formed by neighbouring crystallites.