Basic investigations on zeolite application for electrochemical analysis

Basic investigations on the electrochemical behavior of alumosilicate zeoli tes were conduced in gas atmosphere and aqueous solution using impedance sp ectroscopy under in situ conditions where "zeolitically" bound water molecu les are present in the channel and cage system. Natural stilbite (STI) and heulandite (HEU), zeolites of structure types with the same 4 - 4 = 1 build ing units, were used for these investigations. At a given temperature, well defiined water partial pressures were applied in the gas atmosphere (in situ conditions) and the effect of polar organic molecules on conjuctivity was investigated. Furthermore, the effect of comp lete water saturation of the channel system on the Arrhenius type activatio n energy of conductivity was investigated in aqueous solution in comparison . The ion-exchange behavior of zeolite materials could be monitored under t hese conditions. These results show that, dependent on the different parameters affecting th e zeolite conductivity behavior, they are applicable in the field of electr ochemical analysis if these basic results on single crystals are transferab le to polycrystalline materials.