Reduction of nitrogen monoxide with propene in the presence of oxygen and moisture over gold supported on metal oxides

Abstract

Gold supported on several metal oxides has been prepared with high dispersion by deposition-precipitation and coprecipitation methods. These catalysts are active for the reduction of NO with C 3H 6 in the presence of oxygen and moisture, the reaction temperature varied depending on the kind of metal oxide support and increasing in the order of α-Fe 2O 3 ∼ ZnO < MgO ∼ TiO 2 < Al 2O 3. The highest conversion to N 2 (about 70%) was obtained over Au/Al 2O 3 with a metal loading of 0.1–0.2 wt.-% at 700 K. The conversion of NO to N 2 over Au/Al 2O 3 was not reduced, but slightly increased by the presence of water, although over Al 2O 3 alone it was markedly depressed. Oxygen enhanced the reduction of NO by C 3H 6 and NO 2 reacted with C 3H 6 at lower temperatures than NO, indicating that NO reduction could take place through the oxidation of NO to NO 2, which might then react with C 3H 6.