REDOX BEHAVIOR OF COPPER MORDENITE ZEOLITE

Fourier transform-infrared photoacoustic spectroscopy (FT-IR/PAS) and X-ray diffraction (XRD) techniques have been used to study the reducti on of copper (II) oxide supported on mordenite zeolite, through the ad sorption of carbon monoxide and hydrogen gases at 723 K. It was found that bands due to the bridged hydroxyl groups (3614-3630 cm(-1)) and t he AL-OH groups (3780-3787 cm(-1)) show significant changes upon carbo n monoxide and hydrogen adsorption whereas the Si-OH band did not chan ge after the adsorption. Two further bands were detected at 2156 and 2 297 cm(-1), assigned to carbon monoxide adsorbed on Cu+ species and on the copper-aluminate species, respectively. XRD patterns have demonst rated the proposed interaction between Cu2+ with aluminium mordenite, to form aluminate, whereas FT-IR spectra have established an interacti on between carbon monoxide molecules and the aluminate species.