Interaction of small molecules with transition metal ions in zeolites: The effect of the local environment

Abstract

The interaction of small molecules (CO, NO, NO 2 , N 2 , H 2 O) with transition metal ions inside the zeolite matrix was studied with the combined quantum mechanics/interatomic potential function (QM-Pot) technique. Various sites of the transition metal ions located on the channel wall or on the channel intersection were investigated for ZSM-5 and FER matrices. The interaction of small molecules with transition metal ions leads to changes in structure and coordination of active sites. The extent of these changes depends on the character of the transition metal ion site. The structure, coordination, vibrational analysis, and photoluminescence spectra were investigated and compared with available experimental data (EXAFS, IR, UV-VIS, and EPR). The explanation of differences in catalytic activities of Cu/ZSM-5 and Cu/FER systems is also suggested based on the computational results.