Intracage chemistry: nitrite to nitrate oxidation via molecular oxygen. A Car Parrinello study

Studies in Surface Science and Catalysis 2001, 140, 251-268

Abstract

We present a theoretical study of the oxidation reaction of NO2− to NO3− by dioxygen in the cages of sodalite. The combined Blue Moon Ensemble and Car Parrinello Molecular Dynamics approaches were used.

Our results indicate the active participation of the zeolite framework in the reaction mechanism via the formation of peroxy-like defects. Moreover a molecular level explanation of the experimentally found first order kinetics is given. A spin-unpolarized Density Functional approach has been adopted for the electron-electron interactions, notwithstanding the triplet state is the ground state for molecular oxygen. However our results suggest that interactions in the zeolite cage may reduce the O2 triplet-singlet energy gap, therefore justifying the adopted approximation.