Complete dechlorination of 2,4-dichlorophenol in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel composite electrode

► Pd/PPy-CTAB/foam-Ni electrode with high surface area and low Pd content was prepared. ► The composite electrode was applied to dechlorination of 2,4-DCP in aqueous solution. ► Complete dechlorination of 2,4-DCP was achieved with higher current efficiency. ► Removal efficiency kept 100% after 10 times dechlorination on the stable electrode. ► The electrochemically reductive activation energy was 25.8 kJ mol−1 in this system.