Influence of the guest molecules on the protonic conduction of anhydrous intercalation compounds of α-Zirconium hydrogen phosphate with diamines

Abstract

α-ω alkyl diamines can be intercalated into α-layered zirconium hydrogen phosphate with the formation of compounds of formula α-Zr(HPO 4) 2·N 2H 4(CH 2) n . Anhydrous intercalates with n=0, 2, 3, 4, 5 were characterized by X-ray powder diffractometry and thermogravimetric analysis in order to determine the temperature range at which the anhydrous phase is stable. The ac conductivity was measured with platinum black electrodes on pellets in a dry argon atmosphere. The highest conductivity (}2×10 -6 S cm -1 at 180°C) and the lowest activation energy (0.74 eV) were found for the hydrazine intercalate. At the same temperature the conductivity of the other intercalates is at least 3 orders of magnitude lower with activation energies in the range 0.9 to 1.2 eV, thus showing the protonic transport to be markedly influenced by the basic strength of the diamine.