The mechanism of kinetic oscillations in the catalytic N2O decomposition over Cu-ZSM-5

Oscillations occuring in the catalytic decomposition of N(2)O into the elements over Cu-ZsM-5 were studied at 698 K in integral and gradientless reactors. Transient experiments by using step changes in the nitrous oxide concentration were employed to determine the amounts of adsorbed species in different phases of the oscillations. The experimental results can be modelled by a scheme of five reactions. The proposed reaction mechanism includes the dynamic interaction of two adsorbed species, atomic oxygen and NO(3), and explains the crucial role of nitric oxide, which is formed in a slow side reaction. The results suggest that monovalent copper is the active site for the decomposition of N(2)O, and that this species is involved in a redox cycle. (C) 1999 Elsevier Science Ltd. All rights reserved.