DECOMPOSITION OF NITRIC-OXIDE ON ZIRCONIA IN A SOLID-STATE ELECTROCHEMICAL-CELL

Decomposition of NO has been studied on an electrochemically reduced surface of scandia-doped zirconia. Experiments conducted at 900 °C with mixtures of 2.9 and 5.1 mole percent (m/o) NO in He showed that extremely high decomposition rates can be obtained for NO upon zirconia under sufficiently reducing conditions. These rates are more than six orders of magnitude larger than those found for zirconia under normal conditions, and three orders of magnitude greater than those for supported Pt catalysts. This unusually high reaction rate is evidently due to the presence of a very high concentration of both electrons and oxygen vacancies in the surface region of the electrochemically reduced zirconia. A simple electrochemical cell which eliminates the need for large electrode areas and leak-tight two-compartment geometries which can be used for such purposes has been demonstrated. © 1979, The Electrochemical Society, Inc. All rights reserved.