J. Phys. IV France 7 (1997) C2-903-C2-904
XAFS Study of CuI-Y and CuII-Y Interacting with CO and NOF. D'Acapito1, G. Turnes Palomino2, C. Lamberti3, S. Bordiga3, C. Pazé3, G. Spoto3 and A. Zecchina3
1 C.N.R. Roma Italy, c/o ESRF-GILDA CRG, Grenoble, France
2 Departamento de Química, Universidad de las Islas Baleares, 07071 Palma de Mallorca, Spain
3 Dipartimento di Chimica I.F.M., Via P. Giuria 7, 10125 Torino, Italy
We report a study of the local copper environment in CuI-Y prepared by gas phase reaction of H-Y with CuCl and in CuII-Y prepared by conventional ion exchange with aqueous cupric salt. For the CuI-Y sample, the effect of the interaction with CO and NO will also been reported. XANES, UV-Vis and IR (NO dosed at 77 K) techniques prove that the copper species in the prepared samples have the desired oxidation state. Reduction of CuI-Y with CO leads to the formation of small copper clusters well identified by EXAFS, XANES and UV-Vis spectroscopies, while interaction with NO partially oxydate CuI to CuII. For both as prepared CuI-Y and CuII-Y samples EXAFS does not observe first shell Cu-Cu bond lengths, so excluding the presence of "so called" Cu-dimers in zeolites prepared following our methods.
© EDP Sciences 1997