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

• Published in: Environmental science & technology Vol. 54; no. 1; pp. 559 - 567
• Main Authors: Lou, Yao-Yin, Hapiot, Philippe, Floner, Didier, Fourcade, Florence, Amrane, Abdeltif, Geneste, Florence
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 07.01.2020
• Subjects: Activated carbon; Alachlor; Aqueous solutions; Bismuth; Catalytic activity; Chemical Sciences; Current efficiency; Dechlorination; Electrode materials; Electrodes; Electrowinning; Environmental Engineering; Environmental Sciences; Herbicides; Other; Oxidation; pH effects; Pollutants; Selectivity; Voltammetry; electroreduction; dechlorination; chloracetanilide; chloroacetamide; bismuth
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.9b05732

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.