The self-diffusion parameters of cobalt and nickel into zeolite X and Y, with Si:Al ratios of 1.26, 1.87 and 2.62, were determined at low and high temperatures (figure 15). Derived values of Ea and ΔS were used to suggest which ion sites were involved in the studied diffusion processes.

The Mobility of Cations in Synthetic Zeolites with the Faujasite Framework - VI: The Mobility of Cobalt and Nickel in X and Y Zeolites. A.Dyer, A.B.Ogden: Journal of Inorganic and Nuclear Chemistry, 1975, 37[10], 2207–10