Structure of bimetallic clusters. Extended x-ray absorption fine structure (EXAFS) studies of Rh--Cu clusters

Journal Article · Sat Jan 15 04:00:00 EST 1983 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.444789· OSTI ID:6542804

Meitzner, G; Via, G H; Lytle, F W; Sinfelt, J H

An investigation of the structure of the bimetallic clusters present in rhodium--copper catalysts was conducted with the use of extended x-ray absorption fine structure (EXAFS) measurements. Two catalysts were studied, both employing silica as a support for the clusters and both containing 1 wt. % rhodium. In one catalyst the Cu:Rh atomic ratio was 1:2 and in the other 1:1. Studies were made of the EXAFS associated with the K absorption edges of the rhodium and copper. The results of the EXAFS studies indicate that copper concentrates at the surface of the rhodium--copper clusters. In this regard the results are similar to our earlier reported results on ruthenium--copper clusters. However, the extent of surface segregation of the copper appears to be less pronounced for rhodium--copper clusters. This result is reasonable on the basis that rhodium and copper, unlike ruthenium and copper, exhibit at least some miscibility in the bulk.

• Research Organization: Corporate Research Science Laboratories, Exxon Research and Engineering Company, Linden, New Jersey 07036
• OSTI ID: 6542804
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 78:2; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
CATALYSTS
COPPER
ELEMENTS
FINE STRUCTURE
METALS
MOLECULAR STRUCTURE
MOLECULES
PLATINUM METALS
RHODIUM
SOLID CLUSTERS
SPECTRA
TRANSITION ELEMENTS
X-RAY SPECTRA