Dechlorination of chloroaromatics by electrocatalytic reduction over palladium-loaded carbon felt at room temperature

• Published in: Chemosphere (Oxford) Vol. 39; no. 11; pp. 1819 - 1831
• Main Authors: Tsyganok, Andrey I., Yamanaka, Ichiro, Otsuka, Kiyoshi
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-11-1999; Elsevier
• Subjects: Applied sciences; carbon felt; Chemistry; chloroaromatics; electrocatalysis; Electrochemistry; Exact sciences and technology; General and physical chemistry; General purification processes; Kinetics and mechanism of reactions; palladium; Pollution; reductive dehalogenation; Wastewaters; Water treatment and pollution; Japan; reductive dehalogenation; palladium; chloroaromatics; electrocatalysis; carbon felt; Palladium; Electrode material; Polycyclic aromatic compound; Carbon; Supported catalyst; Chemical reduction; Electrocatalysis; Dechlorination; Organochlorine compounds; Chlorine Organic compounds; Reaction mechanism; Phenols; Aromatic compound; Physicochemical purification; Waste water purification; Electrochemical reaction; Chemical reactivity; Comparative study; Organic compounds; Halogen Organic compounds; Modified material
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/S0045-6535(99)00075-2

The selective dechlorination of various chloroaromatics in water-MeOH medium containing trifluoroacetic acid and tetraalkylammonium salts was successfully performed over Pd-loaded carbon felt cathode at room temperature. The reactivities of 2,4-dichlorophenyl derivatives varied in the order: 2,4 dichlorotoluene < 2,4-dichlorophenol ≤ 2,4-dichloroanisole ≤ 2,4-dichlorobenzoic acid < 2,4-dichlorophenoxyacetic acid < 2,4-dichlorophenethyl alcohol. For 2,4-dihaloanisoles, the ease of reductive cleavage of CX (X=halogen) bond was as follows: F ⪡ Cl < Br. For monochlorobiphenyls, the dechlorination and product recovery efficiencies were remarkably affected by tetraalkylammonium cations of different size. The reaction scheme for the selective electrocatalytic dehalogenation of haloaromatics over Pd-loaded felt cathode was proposed.