Transition metal-promoted oxidation catalysis by fluorite oxides: A study of CO oxidation over Cu-CeO2

In this paper, the Cu-CeO2 system is chosen as a model catalyst and CO oxidation is used as a probe reaction to illustrate the strong interaction and synergism observed when transition metal-promoted fluorite oxides are used as total oxidation catalysts. It was found that only small amounts of copper are sufficient to promote the catalytic activity of CeO2 by several orders of magnitude, while excessive amounts of copper (Cu/(Cu + Ce) > 0.05) are detrimental to the catalyst thermal and hydrothermal stability. Heating the catalyst to temperatures over 800 degrees C has a significant impact on the catalytic activity because of crystal growth of cerium oxide, loss of surface oxygen, and copper aggregation.