Influence of supports on the activities of copper oxide species in the low-temperature NO plus CO reaction

Activity measurements were made of the NO+CO reaction over a series of CuO/CeO2 and CuO/gamma -Al2O3 catalysts with various loading amounts of CuO at low-temperatures, XRD, TPR, UV-DRS and XPS were also used for the characterization of the catalysts. The results show that NO conversions have an intimate relation with the loading amount of CuO and the supports used at temperature lower than 200 degreesC, and the activities decreased in the order: CuO/CeO2 > CuO/gamma -Al2O3 > crystalline CuO. Under these reaction conditions, the activities of the catalysts strongly depended on the surface dispersed copper oxide species. When the temperature was increased to 300 degreesC, NO completely conversed to N-2 over the catalysts, which meant that the temperature had strongly influenced the reaction. The influence of the support on the activities of the supported copper oxide species was tentatively discussed in the view of the strong interactions between active components and the supports which significantly promoted the reduction of the surface dispersed copper oxide species. (C) 2001 Elsevier Science B.V. All rights reserved.