Nitrous oxide decomposition over transition metal exchanged ZSM-5 zeolites prepared by the solid-state ion-exchange method

摘要

This paper studied nitrous oxide decomposition over a series of transition metal exchanged ZSM-5 zeolites prepared by solid-state ion-exchange method. Crystallographic structure of the catalysts has been investigated with the aid of XRD analysis. The texture of the prepared catalysts was investigated using nitrogen sorption. FTIR measurements applying pyridine as a probe molecule have been carried out in order to investigate the nature of the acid sites of the different catalysts. In situ electrical conductivity measurements were carried out in order to relate the activity of this series of catalysts to their electrical conductivity variation in the presence of N2O. The obtained results revealed that the N2O decomposition activity is related to the relative conductivity decrease upon the admission of N2O over metal exchanged ZSM-5 zeolites. Further studies have been performed over Co-, Cu- and Fe-ZSM-5 catalysts since they showed the highest activity patterns among all the tested catalysts. Such studies included the effect of changing Si/Al ratio, the exchange level, the calcination temperature and the milling time.