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Mössbauer Analysis of Iridium in Pt-Ir/SiO2 Catalysts

Published online by Cambridge University Press:  28 February 2011

J. A. Sawicki
Affiliation:
Chalk River Nuclear Laboratories, Chalk River, Ontario KOJ 1JO, Canada
F. E. Wagner
Affiliation:
Department of Physics, Technical University of Munich, D-8046 Garching, Federal Republic of Germany
J. H. Rolston
Affiliation:
Chalk River Nuclear Laboratories, Chalk River, Ontario KOJ 1JO, Canada
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Abstract

The state of iridium in highly dispersed bimetallic Pt-Ir catalysts supported on amorphous silica was studied by 193Ir Mössbauer spectroscopy, after deposition via ion exchange, as well as after calcination, reduction in hydrogen, and on exposure to carbon monoxide. Characteristic patterns and relative contributions of adsorbed [Ir(NH3)5Cl] complexes, IrCl3, IrO2 and Pt-Ir alloy particles have been identified. The composition of bimetallic particles indicates a strong tendency for segregation of Pt and Ir.

Type
Research Article
Copyright
Copyright © Materials Research Society 1988

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