Interaction between water/hydrogen and oxide ceramics

A significant interaction was observed between water vapor and ionic or mix ed conducting oxides as that found in proton conducting ceramics. For the c ase of yttrium substituted zirconium oxide (YSZ), the oxygen exchange on th e 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 t o be much faster than the reaction between oxygen gas and vacancy, which wa s observed as very large values of rate constant for oxygen tracer exchange reaction on YSZ in (H2O)-O-18 + O-18(2) atmospheres at T = 773 K. The inte rfacial resistance of platinum electrode/YSZ electrolyte significantly decr eased in humid atmospheres at T = 761 K.