Transport numbers from hydrogen concentration cells over different oxides under oxidising and reducing conditions

摘要

Partial hydrogen ion conductivity in acceptor doped CaTiO3, BaCeO3 and ZrO2 and nominally undoped BaTiO3 and TiO2 has been investigated by transport number measurements using the hydrogen concentration cell/EMF method in wet atmospheres as a function of pO(2) (10(-20)-1 atm) at 800 or 1000 degreesC. All oxides investigated, except ZrO2, show minor proton conductivity in oxidising atmospheres. Earlier indications of apparent negative charge transport by hydrogen under reducing conditions and high temperatures in SrTiO3 samples have been reproduced for all the investigated oxides including ZrO2.