Catalytic reduction of organohalides at hemin and hemin-imidazole polymer films on pyrolytic graphite electrodes

The electrochemical properties of cast films of hemin-dioctadecyldimethylam monium bromide and a hemin-imidazole complex polymer, HmP, on basal plane p yrolytic graphite (BPG) electrodes were investigated and compared to those previously reported at a hemin cast (or adsorbed) film on a BPG electrode a nd at a HmP-modified edge plane pyrolytic graphite electrode. By means of f our different electrodes, modified with cast (or adsorbed) films of hemin, hemin-dioctadecyldimethylammonium bromide and HmP, as well as of adsorbed h emin film on BPG electrodes, we explored the possibility of the catalytic r eduction of organohalides including trichloroacetic acid, dichloroacetic ac id, dichloroacetonitrile, dichloroacetone, chloral hydride, monochloroaceti c acid, trichloroethanol, tetrachloroethylene, 1,1,1-trichloroethane, chlor oform and 1,1,1-trichloroethane. It tvas found that all of these electrodes reduce trichloroacetic acid, dichloroacetic acid, dichloroacetonitrile, di chloroacetone and chloral hydride catalytically. Among the four modified el ectrodes, the efficiency of the catalytic reduction is the highest at the H mP-modified electrode. (C) 2000 Elsevier Science B.V. All rights reserved.