Continuous wave EPR, pulsed EPR and FT-IR characterization of copper-exchanged mordenites and beta zeolites

Zeolites in which Cu2+ ions substitute for Na+ ions are characterized by electronic properties rather sensitive to their stereochemistry.On the other hand, stereochemistry can also be influenced by many phenomena, such as Jahn-Teller effect, formation of bonds with ligands, d levels shifts caused by crystal field, and semi-coordination involving pi ligands. In the present communivation we compare the influence of stereochemistry on electronic properties of Mordenites and Beta zeolites, and the variation of these properties during their catalytic use for ammoxidation of 1-Methylnaphthalene to 1-Cyanonaphthalene. Fourier Transform Infra Red, Electron Paramagnetic Resonance, Field Sweep two-pulse Electron Spin Echo and Electron Spin Echo Envelope Modulation techniques were employed to better characterize the different samples before and after their catalytic use.