Interaction between Water/Hydrogen and Oxide Ceramics

Abstract

A significant interaction was observed between water vapor and ionic or mixed conducting oxides as that found in proton conducting ceramics. For the case of yttrium substituted zirconium oxide (YSZ), the oxygen exchange on the surface is found to be governed by the interaction of water molecule and oxygen vacancy of YSZ in a humid atmosphere. This reaction rate was found to be much faster than the reaction between oxygen gas and vacancy, which was observed as veiy large values of rate constant for oxygen tracer exchange reaction on YSZ in H218O + 18O2 atmospheres at T = 773 K. The interfacial resistance of platinum electrode/YSZ electrolyte significantly decreased in humid atmospheres at T = 761 K.