Ionic conductivity curves of powder zeolite Y and mordenite encapsulating initially cobalt, nickel or copper cations, was determined by the
shift of the cut-off frequency of the imaginary part of their complex impedances for temperatures lower than 650 ◦C. We have shown that zeolite
Y containing nickel cations has 1 eV as activation energy in the range of temperature [530–600 ◦C], and with the addition of a small quantity of
lithium its conductivity curve has undergone a shift towards lower energies. In addition, in the range [445–600 ◦C], cobalt cations in zeolite Y have
a conductivity coefficient in the vicinity of [0.89–2.77]×10−6 
−1 m−1 and activation energy 0.88 eV. With the lithium addition these values was
changed, respectively, to [0.13–1.44]×10−6 
−1 m−1 and 1 eV in the range [405–600 ◦C].
The same observations were obtained for copper cations in mordenite. The conductivity of this sample was changed from
[1.12–4.25]×10−6 
−1 m−1 in the narrowrange [550–650 ◦C] to [0.06–4.04]×10−6 
−1 m−1 in the wider one [370–650 ◦C] after lithium addition.
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