Abstract
Quantum mechanical (QM) andQM/molecu lar mechanics (MM) studies of the full catalytic cycle of N2O reduction by CO in Fe- BEA zeolite, that is, oxidation of BEA-Fe by N2O andred uction of BEA-Fe-?O by CO, is presented. A large QM cluster, representing half of the channel of the BEA zeolite, is used. The contribution of the MM embedding to the calculated activation energies is found to be negligible. The minimum-energy paths for N2O decomposition and reduction with CO are calculated using the nudged elastic band(NEB) method. Calculatedand experimental activation energies are in goodagreement. The two possible orientations for the gaseous molecules adsorbing on the Fe site that are found lead to different activation energies.