Effect of Adsorbed Phases on the Electrical Conductivity of Synthetic Crystalline Zeolites

Abstract

The electrical conductivity of Linde synthetic crystalline zeolites type X and type A has been measured as a function of various adsorbed phases in the crystals. The potential energy barrier for the conduction process is decreased by the interaction of the adsorbed molecules with the electrostatic field or the field gradient in the lattice. Polar molecules, such as water and ammonia, exhibit a strong association through ion-dipole interactions with the most mobile cations. The mechanism of adsorption of various molecules and the self-diffusion of sodium ions in these phases at discussed in terms of changes in the activation energy, free energy, and entropy of the conduction process. The relative importance of the electrostatic, dispersion, and quadrupole contributions to the interaction energy of the adsorbate with the zeolite is described.