Selective catalytic oxidation of carbon monoxide with carbon dioxide, water vapor and excess hydrogen on CuO–CeO 2 mixed oxide catalysts

Abstract

A series of CuO–CeO 2 catalysts with Cu content in the range of 5–50 at.% (the atomic percent of Cu/(Cu + Ce)) were prepared by co-precipitation method. The catalysts were tested for CO oxidation and selective CO oxidation with CO 2, H 2O and excess H 2. The catalysts were highly active in the CO oxidation and also active and remarkably selective in the selective oxidation. CO 2 and H 2O, however, decreased the catalyst activity; between CO 2 and H 2O, H 2O decreased the activity more than CO 2. Among the catalysts, the 10 at.% Cu catalyst outperformed all the other catalysts in the CO oxidation without CO 2 and H 2O in the feed, whereas the 20 at.% Cu exhibited the highest activity in the selective CO oxidation. This change in the optimum Cu content could be ascribed to the adverse effect of H 2O on the activity that was dependent on the Cu content of the catalysts.