Influence of treatment conditions on decomposition activity of N2O over FeZSM-5 with high iron content

Abstract

The influence of treatment on formation and activity of surface oxygen over FeZSM-5 with high iron content was studied by using a transient multipulse technique combined with temperature-programmed desorption (TPD) and steady-state kinetics. All samples after various treatments were characterised by N₂ sorption, NH₃-TPD, H₂-TPR, and DR-UV–vis. Multipulse experiment results showed that the reductive and inert treatments increase the amount of surface oxygen species formed from N₂O. However, the oxidative treatment inhibits almost half of the oxygen formation. High temperature treatment increases not only the surface oxygen amount but also steady-state decomposition of N₂O. Based on TPD and CO oxidation with surface oxygen, the active oxygen species formed from N₂O are desorbed at low temperature and their amounts increase with oxidative and vacuum treatments and decrease with high temperature treatment. Vacuum treatment in a batch system increases the amount of surface oxygen and prevents transformation of active oxygen species to inactive oxygen species.