Polarization conductivity in dehydrated zeolites NaY and HY

Abstract

The ionic conductivity of the dehydrated faujasite zeolites NaY and of its protonated form HY is determined experimentally by low-frequency impedance spectroscopy. Experiments were carried out in the frequency range 10 Hz-10 MHz at temperatures from ambient to 634 K. It is clearly shown that the measured conductivity could be considered as a sum of two terms. The dc term obeys the Arrhenius equation while the polarization term could be expressed as Aω 8. The conduction phenomena, including the polarization processes, are ascribed to cation movements localized in supercages. Moreover, it is found that the parent zeolite NaY is more conductive than its protonated form HY.