Influence of isomorphous substitution on NO and N2O thermochemistry on Au/ZSM-5 catalyst

摘要

Density functional calculations have been carried out to investigate the effects of the Al isomorphic substitution by B and Ga on the geometries, adsorption energies and vibrational frequencies of NO and N2O on a model for Au(I) ion-exchanged ZSM-5 catalysts. It is shown for first time, that the adsorption of NO, two NO, and N2O are thermodynamically more favored on Au/[B]ZSM-5 than on Au/ [Al]ZSM-5 or Au/[Ga]ZSM-5. The isomorphous substitution in ZSM-5 affects the electronic properties of Au(I), reducing the band gap HOMO-LUMO, favoring the NO adsorption. (c) 2008 Wiley Periodicals, Inc.