Characterization of Pd-Cu alloy nanoparticles on gamma-Al2O3-supported catalysts.
Cu-Pd/Al2O3 bimetallic catalysts have been characterized by XRD, TEM, and EDX techniques. The surface structure has been investigated by FT-IR spectroscopy of low-temperature adsorbed CO in the reduced and in the oxidized state. Evidence has been provided of the formation of Cu-Pd alloy nanoparticles, both of the alpha-phase (disordered fcc) and of the beta-phase (ordered CsCl-type). IR spectra suggest that Cu likely decorates the edges while Pd mostly stays at the main faces. Part of copper disperses as Cu+ on the support even after reduction. The presence of copper seems to modify strongly the sate of oxidized Pd centers in oxidized high-Pd content materials. The redox chemistry of the system, where Pd is reduced more easily than Cu, appears to be very complex.
Sanchez-Escribano
Vicente
V
Laboratorio di Chimica delle Superfici e Catalisi Industriale, Dipartimento di Ingegneria Chimica e di Processo, Università di Genova, P.le Kennedy, I-16129 Genova, Italy.
Arrighi
Laura
L
Riani
Paola
P
Marazza
Rinaldo
R
Busca
Guido
G