BaCe1-x-yZrxYyO3-d Proton Conductors: The Role of the Synthetic Route on their Properties

Proton conducting electrolyte materials are promising candidates for the development of low temperature solid oxide fuel cells. Among them, various doped barium cerate compounds, such as BaCe1-xYxO3-´, have been intensively investigated because of their high proton conductivity. As a drawback, cerates are chemically unstable in CO2-containing atmospheres, such as in case of hydrocarbon or syngas fuelled fuel cells. Conversely, doped barium zirconates electrolyte materials exhibit high chemical stability but lower proton conductivity. A goal of this work was to obtain full-density proton conducting materials having both high conductivity and good chemical stability. In particular, the compositions investigated in this work were BaCe1-x-yZrxYyO3-´ (x=0, 0.1, 0.2, 0.3, 0.4; y=0.15, 0.20). The partial substitution of Ce by Zr in doped barium cerate considerably increased their chemical stability in CO2 atmosphere without sensibly affecting the conductivity.