NO reduction with CO on Cu-Cr and Co-Cr oxide catalysts supported on Al2O3 and Al2O3 + SiO2

Cu-Cr and Co-Cr oxide systems supported on Al2O3 and Al2O3 + SiO2 were studied in order to find the appropriate combination as a catalyst for the reduction of NO with CO with respect to the active phase and the nature of the support. The catalysts were prepared by successive impregnation of the support with solution mixtures of tartaric acid and nitrate. The catalysts were characterized by atomic absorption spectroscopy (AAS), Brunauer, Emmett, Teller (BET), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. The copper-chromium catalysts are more active than the cobalt-chromium ones. The catalysts supported on Al2O3 + SiO2 are more active than the supported on pure alumina. The probable reasons are the higher content of copper and cobalt on the surface of Al2O3 + SiO2 and a formation of less active in the studied reaction copper and cobalt aluminates on the alumina supported catalysts.