title: Effect of silver or copper middle layer on the performance of palladium modified nickel foam electrodes in the 2-chlorobiphenyl dechlorination.
abstract: To enhance the activity of chemi-deposited palladium/nickel foam (Pd/Ni) electrodes used for an electrochemical dechlorination process, silver or copper was deposited electrochemically onto the nickel foam substrate (to give Ag/Ni or Cu/Ni) before the chemical deposition of palladium. The physicochemical properties of the resulting materials (Pd/Ni, Pd/Ag/Ni and Pd/Cu/Ni) were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and their electrochemical catalytic activities were evaluated by monitoring the electrochemical dechlorination of 2-chlorobiphenyl (2-CB) in strongly alkaline methanol/water solution. The results show that the Pd/Ag/Ni and Pd/Cu/Ni electrodes had consistently higher electrocatalytic activities and current efficiencies (CEs) compared with the untreated Pd/Ni electrode. The Pd/Ag/Ni electrode exhibited the highest activity. The dechlorination was also studied as a function of Pd loading, the Ag or Cu interlayer loadings, and the current density. The Pd loading and the interlayer loadings both had positive effects on the dechlorination reaction. Increasing the current density increased the reaction rate but reduced the CE. The improvement of the electrocatalytic activities of the Pd/Ni electrode by applying the interlayer of Ag or Cu resulted from the enlargement of the effective surface area of the electrode and the adjustment of the metal-H bond energy to the appropriate value, as well as the effective adsorption of 2-CB on Ag. Moreover, the high catalytic activity of the Pd/Ag/Ni electrode was maintained after six successive cyclic experiments, whereas Pd/Cu/Ni electrodes deactivate severely under the same conditions.
authors: College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, People's Republic of China.
authors: Zhiqiao
authors: Z
authors: He
authors: Junjun
authors: J
authors: Sun
authors: Jie
authors: J
authors: Wei
authors: Qiong
authors: Q
authors: Wang
authors: Chengxiang
authors: C
authors: Huang
authors: Jianmeng
authors: J
authors: Chen
authors: Shuang
authors: S
authors: Song
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry*; D002384:Catalysis; D002627:Chemistry, Physical; D002713:Chlorine / Q000737:chemistry* / Q000302:isolation & purification; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D004867:Equipment Design; D000432:Methanol / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001713:Biphenyl Compounds; D014867:Water; C055142:2-chlorobiphenyl; D012834:Silver; D002713:Chlorine; D010165:Palladium; D003300:Copper; D009532:Nickel; D000432:Methanol