Ai. Tsyganok et al., Dechlorination of chloroaromatics by electrocatalytic reduction over palladium-loaded carbon felt at room temperature, CHEMOSPHERE, 39(11), 1999, pp. 1819-1831
The selective dechlorination of various chloroaromatics in water-MeOH mediu
m containing trifluoroacetic acid and tetraalkylammonium salts was successf
ully performed over Pd-loaded carbon felt cathode at room temperature. The
reactivities of 2,4-dichlorophenyl derivatives varied in the order: 2,4-dic
hlorotoluene < 2,4-dichlorophenol less than or equal to 2,4-dichloroanisole
less than or equal to 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. Fo
r 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 ha
loaromatics over Pd-loaded felt cathode was proposed. (C) 1999 Elsevier Sci
ence Ltd. All rights reserved.