The adsorption of NO2 and the NO+O2 reaction on Na-Y,FAU:: an in situ FTIR investigation

The adsorption of NO and NO2 and the reaction between NO and O(2)were investigated on a Na-Y,FAU zeolite. The interaction between NO and Na-Y is weak and no IR absorption feature is seen upon room temperature adsorption. On the other hand, several NO, species were identified in the adsorption of NOx bonded to Lewis acidic (NO3-, NO2-) and basic sites (NO+ and [NO+][NO2] and [NO+][N2O4]). In the NO + O-2 reaction, N2O3 was formed and adsorbed N2O3 was observed in addition to the species detected upon NO, adsorption. A series of experiments were conducted to unambiguously assign the IR features in the 2000-2120 cm(-1) spectral range. Through reaction and isotopic substitution ((NO)-N-15 and O-18(2)) experiments, these bands were assigned to NO+ adsorbed onto framework O- sites as charge compensating cations.