The electrochemical hydrodehalogenation of 2,4-dibromophenol has been studied by electrochemical reduction in H-cells and solid polymer electrolyte cells using catalyzed cathodes. 2,4-Dibromophenol inhibits the microbial activity in marine sediments. The electrochemical hydrodehalogenation of 2,4-dibromophenol has been studied by electrochemical reduction in H-cells and solid polymer electrolyte cells using catalyzed cathodes. 2,4-Dibromophenol inhibits the microbial activity in marine sediments.