Preparation and Characterization of Copper and/or Cerium Catalysts Supported on Alumina or Ceria

Catalysts combined from (Al , Ce , and Cu ) were prepared by impregnating copper, cerium nitrates, or both of them onto alumina in order to decrease the diesel soot by complete oxidation. The specific surface area of these catalysts changes by about 8% between the calcination temperature of 300°C and 500°C. However, it greatly decreases beyond 500°C. It has been noted that, when impregnating copper and cerium on alumina , copper has a higher effect upon the specific area compared to cerium s effect, and that the nitrates decomposition on alumina takes place in temperature ranging between 200°C and 400°C. It has been also noted that, when reducing these catalysts at different temperatures with an atmosphere of hydrogen, the more the percentage of copper is higher in the catalysts, the more easily the copper oxide reduces. The use of CeO2 as a support, decreases the reduction temperature of copper oxide Cu+2 compared to Al2O3. However, copper is modified with cerium CuCe/Al2O3 the CeO2-x has no effect on the reduction temperature of Cu+2.