Copper promoted ceria–zirconia based bimetallic catalysts for low temperature soot oxidation

In this investigation, ceria–zirconia composite oxide based monometallic (CoO/CeO2–ZrO2 and NiO/CeO2–ZrO2) and bimetallic (CuO–CoO/CeO2–ZrO2 and CuO–NiO/CeO2–ZrO2) catalysts were evaluated for soot oxidation. These catalysts were prepared by co-precipitation and impregnation methods, and were characterized by X-ray diffraction, Raman spectroscopy, temperature programmed reduction and BET surface area techniques. Characterization results reveal formation of spinel phases in various samples, and Ce1−xCuxO2 solid solution in case of CuO–CoO/CeO2–ZrO2 sample. Among various catalysts investigated, the CuO–CoO/CeO2–ZrO2 combination exhibited a high activity and nearly 100% selectivity towards CO2.