NO Reduction by CO Catalyzed with Au/TiO₂ in Oxygen-rich Condition

Abstract

Gold nanoparticles supported on titania catalysts with different Au loadings were prepared and evaluated in the reaction of NO reduction by CO in an oxygen rich condition. The crystalline structures of the Au/TiO 2 materials were refined with Rietveld method. TiO 2 support chiefly contains anatase phase, having a crystalline size ranged from 5 to 15 nm. Au particles have an average crystal size approximately 2-5 nm as Au concentration less 3 wt %. In the reaction of NO + CO + O 2 , the Au/TiO 2 catalysts show a selectivity to 100 % N 2 , neither NO 2 nor N 2 O was yielded in the reaction temperature between 25 and 400 ºC, which strongly indicates that Au/TiO 2 catalysts are much superior to the other catalysts like Pt/TiO 2 catalysts on which N 2 O was usually produced in the reaction temperature below 200 °C and NO 2 was produced in the reaction temperature above 300 °C under a similar reaction condition.