J. Phys. IV France 7 (1997) C2-905-C2-906
CuI Sites in CuI–ZSM–5 : A XAFS, IR and Computer Graphics StudyC. Lamberti1, M. Salvalaggio1, S. Bordiga1, F. Geobaldo2, G. Spoto1, A. Zecchina1, G. Vlaic3 and M. Bellatreccia4
1 Dipartimento di Chimica I.F.M., Via P. Giuria 7, 10125 Torino, Italy
2 Dipartimento di Scienza dei Materiali e Ingegneria Chimica Politecnico Torino, Italy
3 Dipartimento di Scienze Chimiche e Sincrotrone Trieste SCpA, Trieste, Italy
4 Dipartimento di Chimica Università "La Sapienza", Roma, Italy
IR and XAFS have been employed to investigate the local environment of CuI in CuI-ZSM-5 prepared by gas phase reaction of H-ZSM-5 with CuCl. Both XAFS and IR measurements show that copper species are momodispersed Cu ions, occupying highly unsaturated sites easily accessible to small ligand molecules. CuI-ZSM-5 prepared in this way represent a model solid for investigating the structure of isolated CuI sites in zeolites. EXAFS analysis reveal that, in vacuum conditions, CuI cations are surrounded by 2.5 ± 0.3 oxygens at 2.00 ± 0.02 Å. The combined use of EXAFS, IR and computer graphic simulations allows to infer that CuI ions in CuI-ZSM-5 are located in two families of sites.
© EDP Sciences 1997