Structural study on Si O2 porous gels doped with copper ny using x-ray absorption spectroscopy

Si O2 porous matrix were prepared by sol-gel method and doped with copper adding Cu Cl and Cu SO4. The samples were prepared in monolithic shape, were dried at 1100 deg C. The structural evolution of these gels was studied by X-ray Absorption Spectroscopy (EXAFs and Xanes). The obtained spectra show the formation of Cu O phase in the samples prepared from Cu Cl and treated at 900 and 1100 deg C. In the samples prepared from Cu SO4 occur the formation of Cu O at 900 deg C and Cu2 O at 1100 deg C. (author)