Direct catalytic decomposition of NO with Cu–ZSM-5: A DFT–ONIOM study

Abstract

ONIOM calculations for the direct catalytic decomposition mechanism of NO 2 and NO by Cu–ZSM-5 were carried out. In two layer calculations, Density Functional Theory and Universal Force Field were employed for the high and low level models, respectively. Δ H° and Δ G° evaluations were performed in order to determine the thermodynamically more favored way for catalytic decomposition of NO 2 and NO. The results show that a novel copper κ 2 mononitrosyl species (Z– 2Cu–κ 2NO) is in equilibrium with the Z– 2CuNO and Z– 2CuON species. According to our results, the Z– 2Cu–κ 2NO species is the intermediary key of the direct catalytic decomposition mechanism of NO 2 and NO by Cu–ZSM-5.