Ion exchange in chabazite. Part 1.—Sodium and potassium tracer diffusion studies in pure and mixed ionic forms of chabazite

Abstract

²⁴ Na and ⁴²K isotopes have been used to follow the rate of diffusion of Na⁺ and K⁺ ions in pure Na^– and K-chabazites respectively. From these tracer diffusion measurements diffusion co-efficients and energies of activation were derived. The differences between the heats, entropies and free energies of the transition state and the equilibrium state have been calculated.

The same isotopes were used to measure these two tracer diffusion coefficients in chabazites containing various equilibrium ratios of sodium to potassium. Both of these coefficients were found to decrease smoothly as the Na⁺ content of the chabazite increased.