Oxygen surface exchange kinetics of erbia-stabilized bismuth oxide

Abstract

The surface oxygen exchange kinetics of bismuth oxide stabilized with 25 mol% erbia (BE25) has been studied in the temperature and pO 2 ranges 773-1,023 K and 0.1-0.95 atm, respectively, using pulse-response 18O- 16O isotope exchange measurements. The results indicate that BE25 exhibits a comparatively high exchange rate, which is rate determined by the dissociative adsorption of oxygen. Defect chemical considerations and the observed pO 21/2dependence of the rate of dissociative oxygen adsorption suggest electron transfer to intermediate superoxide ions as the rate determining step in surface oxygen exchange on BE25. © 2010 The Author(s).