The effect of NH3 on the ionic conductivity of dehydrated zeolites Na beta and H beta

Abstract

The effect of NH3 in concentrations up to 25 ppm on the electrical properties of the dehydrated forms of the zeolites Na beta and H beta was examined by use of complex impedance spectroscopy in a frequency range of 10 Hz-10 MHz and a temperature range of 400-723 K. Whereas the ionic conductivity of Na beta is unaffected, NH3 promotes proton conduction in H beta. This is reflected by an increase of the specific conductivity, which is directly proportional to the NH3 concentration, as well as by a decrease of the corresponding activation energy. A Grotthus-like conduction mechanism is supposed for the proton transport in the presence of NH3.