J. Phys. IV France 7 (1997) C2-895-C2-896
Phase Behavior of a Pd-Cu Bimetallic Catalyst During Temperature-Programmed ReductionM. Fernández-García1 and G.L. Haller2
1 Instituto de Catálisis y Petroleoquímica, CSIC, Campus Cantoblanco, 28049 Madrid, Spain
2 Chemical Engineering Department, Yale University, 9 Hillhouse Avenue, New Haven, CT06520-8286, U.S.A.
The phase behavior of a 1%Pd-0.5%Cu bimetallic catalyst during reduction has been followed by X-ray absorption near-edge structure (XANES). The analysis of the XANES spectra by Factor Analysis was used to determine that after calcination the active components are hosted in three different phases : a Cu-Pd mixed oxide, PdO and Cun+ ions exchanged into L-zeolite positions. At the Pd K-edge, an intermediate compound is detected in the reduction process. The reduction of the catalyst yields only one phase, a substitutionally disordered Pd50Cu50 alloy.
© EDP Sciences 1997