Mobility of benzene molecules in NaEMT and KL zeolitic nanostructures studied by 2H NMR spin–lattice relaxation experiments

The motions, diffusion coefficients and activation energies of C6D6 in NaEMT (Ea=18.0 kJ/mol) and KL (Ea=7.3 kJ/mol) zeolites have been examined by 2H NMR technique. Two types of movement of C6D6 exist. Below 183 K for KL and 263 K for NaEMT, benzene molecule adsorbed on cation rapidly rotates around its sixfold symmetry axis. Above these temperatures, aromatics are in isotropic motion and jump from one adsorption site to another.