In-situ XAS Study of Catalytic N2O Decomposition Over CuO/CeO2 Catalysts

摘要

We performed in-situ XAS study of N2O decomposition over CuO/CeO2 catalysts. The Cu K-edge and Ce L-3-edge XANES and EXAFS analyses revealed the dynamic and crucial role of Cu2+/Cu+ and Ce4+/Ce3+ ionic pairs during the catalytic reaction. We observed the initial formation of reduced Cu+ and Ce3+ species during activation in helium atmosphere at 400 degrees C, while concentration of these species decreased significantly during steady-state nitrous oxide degradation reaction (2500 ppm N2O in He at 400 degrees C). In-situ EXAFS analysis further revealed a crucial role of copper-ceria interface in this catalytic reaction. We observed dynamic changes in average number of Cu-Ce scatters under reaction conditions, indicating an enlarging of the interface between both copper and ceria phases, where electron and oxygen transfer occurs.