Journal article
Influence of copper loading and surface coverage on the reactivity of granular iron toward 1,1,1-trichloroethane
Environmental science & technology, Vol.40(5), pp.1485-1490
03/01/2006
DOI: 10.1021/es051300p
PMID: 16568760
Abstract
Although iron-based bimetallic reductants offer promise in treating organohalides, the influence of additive mass loading and two-dimensional surface coverage on reductant reactivity has not been fully elucidated. In this study we examine 1,1,1-trichloroethane reduction by Cu/Fe bimetals as a function of Cu loading and surface coverage. Information from a suite of complementary techniques (X-ray photoelectron spectroscopy, Auger electron spectroscopy, and cross-sectional energy-dispersive X-ray spectroscopy) indicates that displacement plating produces a heterogeneous metallic copper overlayer on iron. The dependence of pseudo-first-order rate constants (k(obs) values) for 1,1,1-trichloroethane reduction on Cu loading exhibits two distinct regimes. At Cu loadings less than 1 monolayer equivalent (approximately 10 micromol Cu/g Fe), a pronounced increase in k(obs) is associated with a corresponding increase in the two-dimensional surface coverage of Cu. A weaker dependence of k(obs) on Cu mass is exhibited at loadings in excess of 1 monolayer equivalent, which we ascribe to an increase in the volume of the metallic overlayer. The observed relationship between k(oba) and loading suggests that 1,1,1-trichloroethane reduction occurs on the Cu surface rather than at the interface between the Cu overlayer and the iron substrate.
Details
- Title: Subtitle
- Influence of copper loading and surface coverage on the reactivity of granular iron toward 1,1,1-trichloroethane
- Creators
- Stephen J Bransfield - Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USADavid M CwiertnyA Lynn RobertsD Howard Fairbrother
- Resource Type
- Journal article
- Publication Details
- Environmental science & technology, Vol.40(5), pp.1485-1490
- Publisher
- United States
- DOI
- 10.1021/es051300p
- PMID
- 16568760
- ISSN
- 0013-936X
- eISSN
- 1520-5851
- Language
- English
- Date published
- 03/01/2006
- Academic Unit
- Center for Health Effects of Environmental Contamination; Civil and Environmental Engineering; Public Policy Center (Archive); Chemical and Biochemical Engineering
- Record Identifier
- 9983991992102771
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