X-ray photoelectron spectra of the palladium-iron bimetallic surface used for the rapid dechlorination of chlorinated organic environmental contaminants
- Univ. of Arizona, Tucson, AZ (United States)
- Oak Ridge National Lab., Grand Junction, CO (United States)
Palladized iron (Pd/Fe) has been successfully used for the rapid dechlorination of organic environmental contaminants in aqueous solutions. We have investigated the nature of the Pd/Fe surface by X-ray photoelectron spectroscopy. Our results indicate that the reactive Pd/Fe surface is formed by the stepwise reduction of Pd(IV) in solution to Pd(II), which replaces protons on the hydroxylated iron oxide surface and forms Pd(II)-O-Fe bonds. These bonds are unstable and collapse spontaneously to yield the reactive palladized iron in which the palladium is in the elemental state. Prolonged exposure of this Pd/Fe surface to a saturated solution of aqueous TCE results in the growth of the hydroxylated iron oxide film that deactivates the Pd/Fe surface. The thick hydroxylated iron oxide film can be removed, and the original activity of the Pd/Fe surface can be restored by washing he surface with a dilute acid solution. 5 refs., 6 figs.
- OSTI ID:
- 437390
- Journal Information:
- Environmental Science and Technology, Vol. 30, Issue 12; Other Information: PBD: Dec 1996
- Country of Publication:
- United States
- Language:
- English
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