Electrocatalytic hydrodehalogenation of 2,4-dichlorophenol in aqueous solution on palladium–nickel bimetallic electrode synthesized with surfactant assistance

Hydrodehalogenation (HDH) of 2,4-dichlorophenol (2,4-DCP) on a palladium–nickel (Pd–Ni) bimetallic electrode was investigated in this paper. The Pd–Ni bimetallic electrode was prepared on meshed titanium (Ti) substrate by electrochemical deposition with assistance of sodium dodecyl benzene sulfonate (SDBS). Cyclic voltammetry (CV) results revealed that the hydrogen adsorption peak current value of electrode became larger when SDBS was added in electrode preparation process. The structure and composition of the electrode were characterized by scanning electron microscopy (SEM), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and X-ray diffraction (XRD). Dechlorination experiment was conducted on the Pd–Ni(SDBS)/Ti electrode in the presence of 100 mg L−1 (0.61 mmol L−1) 2,4-DCP. The removal efficiency of 2,4-DCP reached 100% with dechlorination current of 5 mA within 70 min in aqueous solution, meanwhile the current efficiency was 33.9%. The Pd–Ni(SDBS)/Ti electrode exhibits a good application prospect for electrocatalytic degradation of 2,4-DCP.

► Electrocatalytic hydrogenolysis process was applied to hydrodehalogenation.
► The hydrogen adsorption capability increased with the addition of SDBS.
► The addition of SDBS could prevent Pd–Ni particles from aggregating.
► Complete dechlorination of 2,4-DCP in aqueous solution was achieved.