Abstract
The mechanism of trichloroethylene (TCE) dechlorination using Fe-Ni nanoparticles (unsupported and supported) and the mechanism of their corrosion in water were studied. The nanoparticles synthesized were of 3-30 nm dia, and were prepared by mixing aqueous iron and nickel salts together, followed by borohydride reduction. Kinetic and isotope labeling studies of the nano-Ni-Fe particles revealed that the dehalogenation mechanism involves the galvanic corrosion of the iron to protect the nickel, which reduced water to adsorbed and free hydrogen and hydroxide ion. The nickel chemisorbed the hydrogen and hydrogenated TCE to nontoxic hydrocarbons, e.g., ethylene, ethane, butane, and hexane. Monitoring the progress of the dehalogenation reaction showed hydrogenolysis products, e.g., propane, propylene, and other branched and straight C1-C6 hydrocarbons. Dehalogenation reactions were carried out in D2O and H2O to determine the kinetic solvent isotope effect of hydrogen (deuterium) substitution after H2O (D2O) reduction. A primary solvent isotope effect of 14 was observed, indicating the rate-determining step in the dechlorination reaction was the formation of the C-H bond. The corrosion rate was determined by measuring the amount of hydrogen generated during exposure to 1.8 × 10-4 M TCE solution to assess the lifetime of the Fe-Ni nanoparticles. This is an abstract of a paper presented at the 22nd ACS National Meeting (Chicago, IL 8/26-30/2001).
Original language | English (US) |
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Pages (from-to) | 64-66 |
Number of pages | 3 |
Journal | ACS Division of Environmental Chemistry, Preprints |
Volume | 41 |
Issue number | 2 |
State | Published - 2001 |
Event | 222nd ACS National Meeting - Chicago, IL, United States Duration: Aug 26 2001 → Aug 30 2001 |
All Science Journal Classification (ASJC) codes
- General Chemical Engineering