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

Oscillations occuring in the catalytic decomposition of N2O into the elemen ts over Cu-ZsM-5 were studied at 698 K in integral and gradientless reactor s. Transient experiments by using step changes in the nitrous oxide concent ration were employed to determine the amounts of adsorbed species in differ ent phases of the oscillations. The experimental results can be modelled by a scheme of five reactions. The proposed reaction mechanism includes the d ynamic interaction of two adsorbed species, atomic oxygen and NO3, and expl ains the crucial role of nitric oxide, which is formed in a slow side react ion. The results suggest that monovalent copper is the active site for the decomposition of N2O, and that this species is involved in a redox cycle. ( C) 1999 Elsevier Science Ltd. All rights reserved.