Changes in the conductivity and capacity were monitored in situ during dehydration/hydration in a gas flow. It was found that the conductivity was dominated by protonic conduction. At low temperatures, this was facilitated by the presence of water molecules which were adsorbed on the alumina surface. A decrease in conductivity upon heating was linked to dehydration. At temperatures above 200C, the conduction was dominated by proton hopping between OH groups.

Electrical Conductivity of γ-Al2O3 at Atmospheric Pressure under Dehydrating/Hydrating Conditions. M.Caldararu, G.Postole, C.Hornoiu, V.Bratan, M.Dragan, N.I.Ionescu: Applied Surface Science, 2001, 181[3-4], 255-64