Combustion synthesis of copper catalysts for selective CO oxidation

Copper catalysts supported on ceria, zirconia and niobia were prepared by combustion method with urea, containing a CuO loading of 6 wt.%, and tested on selective oxidation of CO. The characterization of the samples by X-ray diffraction (XRD) presented the formation of solid solution on CuO-CeO2 catalyst and a change in crystalline structure of the support with copper insertion on ZrO2 and Nb2O5 catalysts. The analysis of temperature-programmed reduction (TPR) revealed different interaction degrees of copper with the supports, with reduction peaks between 222 and 390 degrees C. The temperature-programmed desorption of CO (TPD-CO) profiles showed formation Of CO2 and H-2 only for the ceria and zirconia catalysts. In relation to the catalytic tests, the CuO-CeO2 catalyst presented the best performance, with CO conversion of 95% at 150 degrees C up to 45 h on stream, and CO2 selectivity of 55%. (C) 2008 Elsevier B.V All rights reserved.