SURFACE OXYGEN SPECIES AS ACTIVE SPECIES IN THE REDUCTION OF NITROGEN-OXIDE BY AMMONIA OVER COPPER VANADATE

Copper orthovanadate was easily reduced at 150 °C by a mixture of NO and NH3 or at 200 °C by CO. A treatment of the partially reduced copper vanadate by oxygen at 200 °C made the vanadates very active catalysts at 150 °C for the reduction of NO by NH3. By temperature programmed desorption techniques, the interaction between adsorbed NO or NH3 and the adsorbed oxygen species was confirmed. From the results of the experiments using isotopes, it is concluded that the reduction would proceed by a mechanism involving adsorbed NO, adsorbed NH3, and the adsorbed oxygen. © 1979, American Chemical Society. All rights reserved.