AC and DC electrochemical investigation of α-zirconium phosphate intercalated with hexamethylenetetramine

The ac-conductivity of α-zirconium phosphate intercalated with hexamethylenetetramine, α-Zr(HPO4)2·nH2O·0.26(CH2)6N4·0.48NH3, has been measured as a function of temperature (–20 to 25 °C) and relative humidity (11–90%) and compared with that of the host compound under the same experimental conditions. The activation energy for conduction increases with decreasing relative humidity from 0.52 to 0.71 eV. Emf measurements suggested that the main charge carriers are protonic species other than protons or hydrated protons. Mass spectrometry coupled with dc-conductivity experiments gave evidence that the intercalation compound is, to some extent, an ammonium ion conductor and that hexamethylenetetramine is oxidized at the anode to yield CO2.