Charge transfer at oxygen/zirconia interface at elevated temperatures

摘要

The present study reports work function changes in cubic yttria-stabilised zirconia (10 mol-percent Y_2O_3) during oxidation and reduction at elevated temperatures. The data for work function changes, determined in the range 773-1173 K, are discussed in terms of the effect of temperature on the oxidation mechanism and related charge transfer at the oxygen/zirconia interface. It was found that oxidation results in oxygen incorporation in the entire temperature range studied, however only at 773 and 1173 K is the surface free of the surface charge produced by oxygen chemisorption. The WF changes are used for the determination of the oxygen chemisorption isobar corresponding to singly ionised atomic oxygen species. Its maximum appears at 1073 K and corresponds to around 41 percent surface coverage. The isobar is considered in terms of the reactivity mechanism between zirconia and oxygen and related charge transfer.