From Electron Density Flow Towards Activation: Benzene Interacting with Cu(I) and Ag(I) Sites in ZSM-5. DFT Modeling

Cu(I) and Ag(I) sites in ZSM-5 and their interaction with adsorbed benzene are studied by DFT cluster modeling aided with NOCV analysis of charge transfer processes. The interplay between donation and back donation from the cation to the ad-molecule, reinforced by the framework environment correlates with benzene activation shown also by the red shift in calculated and measured IR frequencies. Copper sites have better activation ability due to its stronger interaction with the framework, serving as electron reservoir, and better match between d orbitals and pi orbitals of benzene.