enhance the rate of nitrous oxide (N2O) decomposition catalyzed by Fe-ZSM-5 at low temperatures
In the present work, the NO-assisted N2O decomposition over mononuclear iron sites in Fe-ZSM-5 was studied on a molecular level using density functional theory (DFT) and transition-state theory.
A reaction network consisting of over 100 elementary reactions was considered. The structure and energies of potential-energy minima were determined for all stable species, as were the structures and energies of all transition states.
Reactions involving changes in spin potential-energy surfaces were also taken into account. In the absence of NO and at temperatures below 690 K, most active single iron sites (Z-[FeO]+) are poisoned by small concentrations of water in the gas phase; however, in the presence of NO, these poisoned sites are converted into a novel active iron center (Z-[FeOH]+). These latter sites are capable of promoting the dissociation of N2O into a surface oxygen atom and gas-phase N2.