Proton mobility in H-ZSM5 studied by impedance spectroscopy
Abstract The electrical properties of dehydrated zeolite H-ZSM5 with different SiO2/Al2O3 ratios (30, 50, 80, 150, 280, and 1000) were examined by complex impedance spectroscopy. We determined the activation energy for proton relaxation, which depends on the spatial distance of the aluminum sites. Classical hopping theory as well as Debye–Huckel theory are in agreement with the experimental data implying that the relaxation originates from translational proton hopping instead of local reorientational motion, as assumed from 1H-MAS-NMR as well as from quantum-chemical calculations.