Eur. Phys. J. D 7, 89-97 (1999)
https://doi.org/10.1007/s100530050352

Structural characterization of pumice-supported silver-palladium metal clusters by means of XAFS and AWAXS

¹ Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Via E. Fermi, 40, 00044 Frascati, Italy
² Istituto di Chimica e Tecnologia dei Prodotti Naturali del CNR, Via Ugo La Malfa, 153, 90146 Palermo, Italy
³ Dipartimento di Chimica Inorganica, Università di Palermo, Via Archirafi, 26, 90123 Palermo, Italy
⁴ Dipartimento di Fisica, Università di Roma Tre, Via della Vasca Navale, 84, 00146 Roma, Italy

Received: 21 December 1998
Revised: 19 March 1999
Published online: 15 August 1999

Abstract

Silver-palladium bimetallic clusters were synthesized on pumice by the reduction of aqueous solution of metal salts with different Pd:Ag ratios. Used as bimetallic catalysts, in hydrogenation reactions, in situations where molecules can undergo several different reactions, they eliminate undesired reactions and maximize the desired ones. To characterize the structure of these bimetallic catalysts and control if the two metallic elements do mix or not to each other to form an alloy, the structure of the Ag-Pd bimetallic clusters was investigated by means of X-ray-absorption fine-structure spectroscopy (XAFS) and anomalous wide angle X-ray scattering (AWAXS) experiments performed at the European Synchrotron Radiation Facility (ESRF) using the GILDA and the BM16 beamlines. A correlation between Ag and Pd was found but not a clear evidence of alloying.