The activity and selectivity of catalytic peroxide oxidation of chlorophenols over Cu-Al hydrotalcite/clay composite.
J Colloid Interface Sci
; 357(2): 447-52, 2011 May 15.
Article
em En
| MEDLINE
| ID: mdl-21402383
ABSTRACT
Liquid phase catalytic oxidation of chlorophenols (CPs) was carried out over Cu-Al hydrotalcite/clay composite at ambient temperature and pressure using hydrogen peroxide as oxidant. The results showed that the catalyst had high catalytic activity, with complete oxidation of 4-CP within 40 min at 40 °C. The content and position of chlorine on the aromatic ring had significantly different effects on the oxidation rate of CPs, with the rate sequence of phenol > monochlorophenol (MCP) > dichlorophenol (DCP) > trichlorophenol (TCP), 3-CP > 2-CP > 4-CP, and 3,5-DCP > 3,4-DCP > 2,5-DCP > 2,4-DCP > 2,6-DCP. This was ascribed to the interactions among σ-electron withdrawing conductive effect, π-electron donating conjugative effect, and steric hindrance effect of chlorine. It was evidenced that the catalytic peroxide oxidation of CPs in the first step was selective and rate-limiting, where chlorinated 1,4-benzoquinones formed.
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1
Base de dados:
MEDLINE
Assunto principal:
Peróxidos
/
Clorofenóis
/
Cobre
/
Alumínio
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Hidróxido de Alumínio
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Silicatos de Alumínio
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Hidróxido de Magnésio
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article