Electrocatalytic dechlorination of chlorophenols on palladium/graphene-Nafion/titanium mesh electrode

Abstract

The electrocatalytic dechlorination of 3,5-dichlorophenol (3,5-DCP) and 2,3,5-trichlorophenol (2,3,5-TCP) on palladium/graphene-Nafion/titanium mesh electrode (Pd/rGO-Nafion/Ti electrode) was studied. The preparation conditions of Pd/rGO-Nafion/Ti electrode were investigated by electrochemical workstation, and the results showed that the addition of the graphene-Nafion middle layer could improve the electrocatalytic ability. The Pd/rGO-Nafion/Ti electrode was characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and X-ray photoelectron spectroscopy (XPS). The influences of dechlorination current and initial pH value of reaction solution on the conversion efficiency and the current efficiency of dechlorination on Pd/rGO-Nafion/Ti electrode were investigated. Complete dechlorination of 3,5-DCP and 2,3,5-TCP could be achieved within 90 min under initial pH of 2.3 and current of 5 mA. The dechlorination intermediate products of 3,5-DCP and 2,3,5-TCP were detected and the dechlorination pathways were inferred. The kinetics results revealed that the dechlorination of 3,5-DCP and 2,3,5-TCP followed a two-stage mixed order kinetics.