(513de) Enhanced Activity for CO and C3H6 Oxidation By Introducing Pd and Ag on CeO2 | AIChE

(513de) Enhanced Activity for CO and C3H6 Oxidation By Introducing Pd and Ag on CeO2

Authors 

Seo, Y. - Presenter, Korea University
Lee, K. Y., Korea University
Lee, M. W., Korea University
Lee, E. J., Korea University
Low-Temperature Combustion (LTC) engine is developed to obey the automobile exhaust regulation, Euro 6. However, using the LTC technique, the emission of carbon monoxide (CO) and hydrocarbon (HC) increases because the after-treatment catalyst is not active at low temperature. Therefore, developing the exhaust purification catalyst for the oxidation of CO and HC which functions well under 200ºC is essential.

Palladium (Pd) based catalyst has been widely studied for the CO and HC oxidation because of its high performance. Cerium oxide (CeO2) is also well known as a catalyst for the oxidation reaction since it has good redox properties and oxygen storage capacity (OSC). CeO2 easily captures oxygen from the atmosphere and provides the oxygen as a reactant during the oxidation reaction. As Pd is on CeO2, it is proved that the activity of CO and HC oxidation is improved by the metal-support interaction. In this study, silver (Ag) is loaded on CeO2 at first to activate the mobility of oxygen on CeO2 because it is known that Ag has abilities to activate the lattice oxygen and promote the oxygen vacancy formation. It is expected that this process will enhance the oxidation activity of the catalyst. This study is focused on the synergistic effect of Pd, Ag, and CeO2 and the behavior of the catalyst during the CO and HC oxidation reaction.

At first, Ag-CeO2 supports with various amounts of Ag are synthesized and Pd is impregnated on the supports with constant weight percent in this study. Catalytic activity tests of Pd/Ag-CeO2 catalysts were performed with CO, HC, and oxygen as reactants. In addition, characterization analyses such as N2 adsorption and desorption, CO chemisorption, XRD, XPS, and H2-TPR were performed to investigate features of the catalyst.

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