Theoretical Analysis of N2O to N2 Conversion During the Catalytic Decomposition of NO by Cu-Zeolites

Catalytic reactions of N2O in Cu-exchanged silica zeolites (ZSM-5) have been investigated theoretically using first-principles density functional theory (DFT). We consider four possible reaction paths for the production of N2, including (i) ZCu+N2O→ZCuO+N2, (ii) ZCuO+N2O→ZCuO2+N2, (iii) ZCu+NO+N2O→ZCuNO2+N2 and (iv) ZCu+NO2+N2O→ZCuNO3+N2 (“Z” refers to zeolites). Reactions (i) and (iii) are found to be the most favorable, whereas reactions (ii) and (iv) have much larger barriers. The implication for N2O reactions in non-selective reduction of NO by CO is also discussed.