Efficient Dechlorination of α-Halocarbonyl and α-Haloallyl Pollutants by Electroreduction on Bismuth

Environ Sci Technol. 2020 Jan 7;54(1):559-567. doi: 10.1021/acs.est.9b05732. Epub 2019 Dec 27.

Abstract

The electrocatalytic activity of bismuth considered as a low-cost and green electrode material was studied in reductive dechlorination processes. Cyclic voltammetry analyses showed that the Bi electrode exhibited a high catalytic activity to reduce alachlor, a chlorinated herbicide, in the aqueous medium at different pH values. Bulk electrolyses were performed at different potentials and pH values. Alachlor was reduced in deschloroalachlor, its dechlorinated derivative, with a high selectivity (96%) and a current efficiency of 48%. The reductive dechlorination of other chlorinated compounds with an activated carbon atom was then studied, showing that the bismuth electrode catalyzed the electroreduction of chloroacetamides, α-halocarbonyl, and α-haloallyl pollutants. Cyclic voltammetry experiments allowed us to propose a mechanism explaining the high catalytic activity of bismuth to reduce these families of compounds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bismuth*
  • Electrodes
  • Electrolysis
  • Environmental Pollutants*
  • Halogenation

Substances

  • Environmental Pollutants
  • Bismuth