Catalytic properties and electronic structure of copper ions in Cu-ZSM-5

ESR and UV-vis DR spectroscopy have been used to elucidate stabilization conditions of copper ions in Cu-ZSM-5 zeolites as isolated Cu2+ ions, chain copper oxide structures and square-plain oxide clusters. The ability of copper ions for reduction and reoxidation in the chain structures may be responsible for the catalytic activity of Cu-ZSM-5. These transformations of copper ions are accompanied by the observation of intervalence transitions Cu2+-Cu+ and CTLM of the chain structures in the UV-vis spectra.