Electroreduction of nitrate in water: Role of cathode and cell configuration

Ding, Jing; Li, Wei; Zhao, Qingliang; Wang, Kun; Zhou, Zheng; Gao, Yunzhi

doi:10.1016/j.cej.2015.03.001

Cited by 118 publications

(80 citation statements)

References 43 publications

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“…These limitations cause the overall nitrate removal efficiency for the cathode materials tested in this study (Fig 1). Also, the short retention time for the reaction in the flow through system and oxidation of reduction byproducts to nitrate adversely affect the reduction mechanism (Ding et al 2015). However, the repulsion between nitrate and the cathode under high negative potentials might be suppressed by the presence of Na + and Ca + ions which may form ion pairs and ion bridges with the reacting ion (Katsounaros and Kyriacou 2008).…”

Section: Resultsmentioning

confidence: 99%

“…Studies have shown that the efficiency and selectivity of nitrate hydrogenation (chemical and electrochemical) are influenced by the type of catalysts, catalyst support, pH, hydrogen flow and metals ratio in bimetallic electrodes (Pintar et al 1998; Pintar 1999; Prüsse et al 2000; Epron et al 2001; Prüsse and Vorlop 2001; Liou et al 2009; Ding et al 2015). Monometallic Pd catalysts exhibit no activity for nitrate reduction: nitrates do not adsorb on monometallic Pd sites.…”

Section: Introductionmentioning

confidence: 99%

“…solar power). The electrochemical reduction has been investigated for nitrates removal from aqueous solutions (de Vooys et al 2000; Wang and Qu 2006; Li et al 2010; Ding et al 2015; Govindan et al 2015). …”

Section: Introductionmentioning

confidence: 99%

“…However, the use of expensive bulk Pt and Pd is a disadvantage from a practical viewpoint. To address this challenge, the cost-effective materials such as graphite, Ni and Fe were used as cathodes and showed promising results for nitrate removal and selectivity towards nitrogen gas production (Dash and Chaudhari 2005; Wang and Qu 2006; Ding et al 2015). However, these were not intensively investigated so far.…”

Section: Introductionmentioning

confidence: 99%

“…Although the divided cells provide easier control of the conditions since electrolytes are split with the membrane, their use is impractical for the groundwater treatment applications. In addition, it is also noticed that in divided cells, the production of ammonia in catholyte increases over time (Ding et al 2015). The undivided cell has advantages like simpler facility design and lower energy consumption but the water electrolysis products can adversely influence the removal of the target contaminant; oxygen formed at the anode can also be reduced at the cathode, which competes with the reduction mechanisms.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Electrochemically-induced Reduction of Nitrate in Aqueous Solution

Rajic¹,

Berroa²,

Gregor³

et al. 2017

International Journal of Electrochemical Science

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In this study, we evaluated the removal of nitrate from synthetic groundwater by a cathode followed by an anode electrode sequence in the electrochemical flow-through reactor. We also tested the feasibility of the used electrode sequence to minimize the production of ammonia during the nitrate reduction. The performance of monometallic Fe, Cu, Ni and carbon foam cathodes was tested under different current intensities, flow rates/regimes and the presence of Pd and Ag catalyst coating. With the use of monometallic Fe and an increase in current intensity from 60 mA to 120 mA, the nitrate removal rate increased from 7.6% to 25.0%, but values above 120 mA caused a decrease in removal due to excessive gas formation at the electrodes. Among tested materials, monometallic Fe foam cathode showed the highest nitrates removal rate and increased significantly in the presence of Pd catalyst: from 25.0% to 39.8%. Further, the circulation under 3 mL min−1 elevated the nitrate removal by 33% and the final nitrate concentration fell below the maximum contaminant level of 10 mg L−1 nitrate–nitrogen (NO3-N). During the treatment, the yield of ammonia production after the cathode was 92±4% while after the anode (Ti/IrO2/Ta2O5), the amount of ammonia significantly declined to 50%. The results proved that flow-through, undivided electrochemical systems can be used to remove nitrate from groundwater with the possibility of simultaneously controlling the generation of ammonia.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Electrochemically-induced Reduction of Nitrate in Aqueous Solution

Rajic¹,

Berroa²,

Gregor³

et al. 2017

International Journal of Electrochemical Science

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Environmental Remediation with Electrochemical Technologies

Chen

Rajić

Zhao

et al. 2018

Kirk-Othmer Encyclopedia of Chemical Technology

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Significant concerns continue to be raised over environmental pollution of soils and water resources. Chemical fate and transport coupled with redox manipulation are the primary processes that have been considered for removing contamination and minimizing exposure. Electrochemical processes utilize electron transfer to drive transport of chemicals and redox manipulation for treatment of contaminated media. Electrokinetic remediation relies on the electric field to transport contaminants in low permeability soils toward the electrode vicinity for removal. In water cleanup, both electroreduction and electrooxidation have been used. Electroreduction has been used for dechlorination and defluorination of halogenated calcitrant compounds. Electrooxidation has also gained significant potential for transformation of many legacy and emerging contaminants. For example, organic contaminants could be oxidized directly on anode surface (direct anodic oxidation), by electrochemically generated hydroxyl radicals or by other electrochemically generated oxidants (indirect anodic oxidation). In this article, we present an overview of the state‐of‐the‐art electrochemical processes for treatment of contaminated soil and water. We also describe a perspective for future research directions in the field of electrochemical treatment of contaminated media.

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3.4% Solar‐to‐Ammonia Efficiency from Nitrate Using Fe Single Atomic Catalyst Supported on MoS₂ Nanosheets

Zhang

Liu

et al. 2021

Adv Funct Materials

104

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Electrochemical synthesis of NH3 is a carbon-free alternative to the traditional Haber-Bosch process. The challenge with nitrogen reduction reaction (NRR) to NH3 is cleavage of the inert N≡N triple bond of nitrogen gas. Obtaining NH3 from environmental pollutants, such as nitrates or nitrites, is a more practical route than NRR. However, reduction of nitrates or nitrites to ammonia is currently hampered by modest Faradaic efficiencies, typically below 10 %. Here, we report a novel heterogeneous catalyst based on iron (Fe) single-atoms supported on two-dimensional MoS2 (Fe-MoS2) for the nitrate reduction reaction (NO3RR). We have found that Fe-MoS2 exhibits remarkable performance with a maximum Faradaic efficiency of 98 % for NO3RR to NH3 at an overpotential of -0.48 V vs. the reversible hydrogen electrode (RHE) as confirmed by our isotopic nuclear magnetic resonance (NMR) analyses. Density function theory (DFT) calculations reveal that the enhanced selectivity for the production of NH3 from single Fe atoms supported on MoS2 is attributed to a reduced energy barrier of 0.38 eV associated with de-oxidation of *NO to *N -the usual potential limiting step in NO3RR. We assembled our catalyst in a two-electrode electrolyzer coupled to an InGaP/GaAs/Ge triple-junction solar cell to demonstrate a solar-to-ammonia (STA) conversion efficiency of 3.4 % and a yield rate of 0.03 mmol h -1 cm -2 equivalent to 510 µg h -1 cm -2 . Our results open new avenues for design of single-atom catalysts (SAC) for the realization of solar-driven ammonia production.

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Electroreduction of nitrate in water: Role of cathode and cell configuration

Cited by 118 publications

References 43 publications

Electrochemically-induced Reduction of Nitrate in Aqueous Solution

Electrochemically-induced Reduction of Nitrate in Aqueous Solution

Environmental Remediation with Electrochemical Technologies

3.4% Solar‐to‐Ammonia Efficiency from Nitrate Using Fe Single Atomic Catalyst Supported on MoS₂ Nanosheets

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Electroreduction of nitrate in water: Role of cathode and cell configuration

Cited by 118 publications

References 43 publications

Electrochemically-induced Reduction of Nitrate in Aqueous Solution

Electrochemically-induced Reduction of Nitrate in Aqueous Solution

Environmental Remediation with Electrochemical Technologies

3.4% Solar‐to‐Ammonia Efficiency from Nitrate Using Fe Single Atomic Catalyst Supported on MoS2 Nanosheets

Contact Info

Product

Resources

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3.4% Solar‐to‐Ammonia Efficiency from Nitrate Using Fe Single Atomic Catalyst Supported on MoS₂ Nanosheets