Manganese dioxide as a catalyst for oxygen-independent atrazine dealkylation
- Princeton Univ., NJ (United States). Dept. of Chemistry
- Rutgers-the State Univ., New Brunswick, NJ (United States)
- Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.
The herbicide atrazine is widely distributed in the environment, and its reactivity with soil minerals is an important issue. The authors have studied atrazine degradation on the surface of synthetic hydrous (10% H{sub 2}O) {delta}-MnO{sub 2} (birnessite) using UV resonance Raman spectroscopy and gas chromatography. The products are mainly mono- and didealkyl atrazine. Atrazine disappearance is rapid, independent of whether O{sub 2} is present or not. MnO{sub 2} reduction is a minor reaction, and the alkyl chains are converted mainly to the alkenes, in a nonredox process. A novel dealkylation mechanism is proposed involving proton transfer to Mn(IV)-stabilized oxo and imido bonds. When O{sub 2} is present, olefin oxidation and ring mineralization are also observed as secondary reactions in addition to those discussed above. Thus {delta}-MnO{sub 2}, a common soil constituent, is found to promote efficient N-dealkylation of the herbicide atrazine at 30 C, via a nonoxidative mechanism.
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Insts. of Health, Bethesda, MD (United States)
- DOE Contract Number:
- AC03-76SF00098; FG02-97ER14755
- OSTI ID:
- 687355
- Journal Information:
- Environmental Science and Technology, Vol. 33, Issue 18; Other Information: PBD: 15 Sep 1999
- Country of Publication:
- United States
- Language:
- English
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