Byproduct shape selectivity in supercritical water oxidation of 2-chlorophenol effected by CuO/ZSM-5
Reduction of trace polycyclic aromatic hydrocarbon (PAH) byproducts in supercritical water oxidation (SCWO) of 2-chlorophenol (2CP) effected by CuO/ZSM-5 has been investigated in the present work. In the channels of ZSM-5, due to a restricted environment, formation of undesired PAH byproducts in the SCWO of 2CP was significantly suppressed. Only trace light-PAHs with a molecular size less than 6 A were formed in the SCWO of 2CP. Carcinogenic PAHs (heavy-PAHs) were not found. Structures of CuO and Cu{sub 2}O in the channels of ZSM-5 involved in the catalytic SCWO of 2CP were studied by X-ray photoelectron spectroscopy (XPS). The Cu{sub 2}O-to-CuO ratio was approximately 0.15. Existence of Cu(I) and Cu(II) was also confirmed by the preedge X-ray absorption near edge structural (XANES) spectroscopy. The copper oxides with a square-plane structure were observed by electron paramagnetic resonance (EPR) spectra. Furthermore, the extended X-ray absorption fine structural (EXAFS) spectra suggest that the copper oxides in the channels of ZSM-5 may form Cu{sub 3}O{sub 2} clusters with Cu-O bond distances of 2.79 and 1.91 {angstrom}, respectively. The Cu{sub 3}O{sub 2} clusters were oxidized to Cu{sub 3}O{sub 4} by H{sub 2}O{sub 2} in supercritical water.
- Research Organization:
- National Cheng Kung Univ., Tainan (TW)
- OSTI ID:
- 20050874
- Journal Information:
- Langmuir, Vol. 16, Issue 6; Other Information: PBD: 21 Mar 2000; ISSN 0743-7463
- Country of Publication:
- United States
- Language:
- English
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