Dechlorination of chloroacetic acids by electrocatalytic reduction using activated silver electrodes in aqueous solutions of different pH

Xu, Ying; Zhang, Hong; Chu, Cheng Pu; Ma, Chun An

doi:10.1016/j.jelechem.2011.10.010

Cited by 46 publications

(16 citation statements)

References 42 publications

(54 reference statements)

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“…26 Many studies have dealt with aqueous medium to achieve degradation of environmental pollutants such as chlorinated solvents and pesticides. [27][28][29][30][31] Thus, silver cathodes have shown good catalytic activity for the dechlorination of solvents such as polychloromethanes, polychloroethanes, and polychloroethylenes. 28,29,32,33 Total and partial dechlorinations of polychlorophenols and other aromatic species by reduction on silver electrode have also been reported.…”

Section: Introductionmentioning

confidence: 99%

Reductive dehalogenation of a chloroacetanilide herbicide in a flow electrochemical cell fitted with Ag‐modified Ni foams

Lou

Verlato

et al. 2018

J of Chemical Tech & Biotech

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BACKGROUND The aim of this work is to adapt the electrochemical reduction of Alachlor™, using Ag‐modified Ni foam electrodes to environmental applications. In this context, preparative electrolyses of Alachlor™ were performed in a flow electrochemical cell in different electrolytic media. RESULTS The highest catalytic activity for the reduction of Alachlor™ was obtained in 0.05 mol L‐1 NaOH, with a conversion yield of 93%. The dechlorination yield of Alachlor™ estimated from the Cl‐ concentration was 77%, significantly lower than its conversion yield, but higher than the yield of deschloroalachlor (69%), the main dehalogenated by‐product, indicating the presence of other by‐products. CONCLUSIONS Total reduction of Alachlor™ was achieved in conditions adapted to environmental applications, showing that this process can be used for dechlorination treatment of Alachlor™ in aqueous media. Although a high dechlorination yield was obtained, biodegradability estimated from BOD5 measurements remained low, showing that the C–Cl bond is not the only functional group that is responsible for the biorecalcitrance of Alachlor™. © 2017 Society of Chemical Industry

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Section: Introductionmentioning

confidence: 99%

Reductive dehalogenation of a chloroacetanilide herbicide in a flow electrochemical cell fitted with Ag‐modified Ni foams

Lou

Verlato

et al. 2018

J of Chemical Tech & Biotech

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“…Two types of Ag electrodes namely Ag(p) and Ag(r) were used. Ag(p) was made by polishing the bulk metal with 0.3-μm alumina powder, whereas Ag(r) was prepared in 0.5 mol•L -1 NaCl aqueous solution by an oxidation-reduction cyclic process [23][24][25] at a scan rate of 10 mV•s -1 and in the range of -0.4 to 0.4 V, 4 cycles. X-ray photoelectron spectroscopy (XPS, KRATOS AXIS ULTRA DLD) with a monochromatized aluminium X-ray source was used to confirm the chemical states of Ag.…”

Section: Electrodes Preparation and Characterizationmentioning

confidence: 99%

Catalytic Effect of Silver Cathodes on 3,4,5,6-Tetrachloropicolinic Acid Dechlorination in Aqueous Solutions

马红星¹,

葛婷婕²,

蔡倩倩³

et al. 2016

Acta Physico-Chimica Sinica

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Dechlorination of 3,4,5,6-tetrachloropicolinic acid (TeCP) on roughened silver (Ag(r)) cathodes provides an unexpected example showing extraordinary catalytic effect in aqueous solution, which is counter to what has been reported in electrochemical reduction of organic halides using aprotic media. To fully recognize this extraordinary catalytic effect of silver cathodes on electrochemical reduction of 3,4,5,6-tetrachloropicolinic acid in aqueous solutions, we conduct a comprehensive study from the aspect of surface characterization, in situ electrochemical study, and theoretical calculation. Transmission electron microscopy (TEM) images and X-ray photoelectron spectroscopy (XPS) spectra are presented to observe the surface structure and chemical state of Ag(r). Experimental results show that Ag nanoparticle can be formed in the oxidation-reduction cyclic (ORC) process, which leads to an increase in the degree of surface disorder. Density functional theory (DFT) calculations of the first electron transfer (ET) process, integrated with an in situ electrochemical surfaceenhanced Raman spectroscopy (SERS) study and a cyclic voltammetry (CV) experiment with the aid of H + , were performed to characterize various surface species in different electrode potential regions. Experimental evidence shows that the first ET process is catalyzed by silver for the radical derivate (TeCP •-) formed by the ET process

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“…However, Sun et al [6] also noted that the dechlorination efficiency increased gradually as the solution pH decreased, and then became stable after the pH reached a threshold value. In addition, Xu et al [14] reported that, while the dechlorination efficiency of chloroacetic acids remain similar in H 2 SO 4 , Na 2 SO 4 , and NaOH aqueous solutions, a higher current efficiency can be achieved in alkaline aqueous solutions because of less molecular hydrogen evolution. Different model contaminants and dechlorination systems may be responsible for the differential results reported in the literature.…”

Section: Cyclic Voltammetry Experiments Of Different Rate and Cyclesmentioning

confidence: 99%

“…The electrode material and its surface features are principal variables that govern the production of the reactive atomic H, which is available for reduction reactions [13][14][15]. The desired properties can be achieved by using palladiummodified electrodes since the hydrodechlorination is more favorably catalyzed by low hydrogen over-potential metals [16,17].…”

Section: Introductionmentioning

confidence: 99%

Efficient dechlorination of 2,4-dichlorophenol in an aqueous media with a mild pH using a Pd/TiO2NTs/Ti cathode

Bao

2015

Front. Environ. Sci. Eng.

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In this study, palladium-loaded titania nanotubes was fabricated on a titanium plate (Pd/TiO 2 NTs/Ti) for efficient electrodechlorination of 2,4-chlorophenol with a mild pH condition. The nature of Pd/TiO 2 NTs/Ti electrodes was characterized by field-emission scanning electron microscope (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV) techniques. The characterization results indicated the generation of Pd 0 nanoparticles which were evenly dispersed on titania nanotubes arrays on the Pd/ TiO 2 NTs/Ti surface. An effective degradation efficiency of up to 91% was achieved within 60 min at cathode potential of -0.7 V (vs. SCE) and initial pH of 5.5. The effects of the applied cathode potential and initial pH on the degradation efficiency were studied. A near neutral condition was more favorable since very low and very high pHs were not conducive to the dechlorination process. Furthermore, the intermediates analysis showed that the Pd/TiO 2 NTs/Ti electrode could completely remove chlorine from 2, 4-dichlorophenol since only phenol was detected as the byproduct and the concentration of released chlorine ions indicated near-complete dechlorination. This work presents a good alternative technique for eliminating persistent chlorophenols in polluted wastewater without maintaining strong acidic environment.

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Dechlorination of chloroacetic acids by electrocatalytic reduction using activated silver electrodes in aqueous solutions of different pH

Cited by 46 publications

References 42 publications

Reductive dehalogenation of a chloroacetanilide herbicide in a flow electrochemical cell fitted with Ag‐modified Ni foams

Reductive dehalogenation of a chloroacetanilide herbicide in a flow electrochemical cell fitted with Ag‐modified Ni foams

Catalytic Effect of Silver Cathodes on 3,4,5,6-Tetrachloropicolinic Acid Dechlorination in Aqueous Solutions

Efficient dechlorination of 2,4-dichlorophenol in an aqueous media with a mild pH using a Pd/TiO2NTs/Ti cathode

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