Physicochemical properties of RuO2 and IrO2 electrodes affecting chlorine evolutions

Luu, Tran Le; Kim, Jiye; Yoon, Jeyong

doi:10.1016/j.jiec.2014.02.052

Cited by 68 publications

(13 citation statements)

References 31 publications

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“…In 2015, Le Luu et al studied the selectivity between Cl 2 and O 2 evolution in acidic 5 M NaCl solution, comparing IrO 2 and RuO 2 electrodes. The electrochemically active surface areas of the electrodes, which were prepared by conventional thermal decomposition, were determined using CV.…”

Section: Selectivity For Oxygen and Chlorine Evolution In Chlor-alkal...mentioning

confidence: 99%

Selectivity between Oxygen and Chlorine Evolution in the Chlor-Alkali and Chlorate Processes

2016

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Chlorine gas and sodium chlorate are two base chemicals produced through electrolysis of sodium chloride brine which find uses in many areas of industrial chemistry. Although the industrial production of these chemicals started over 100 years ago, there are still factors that limit the energy efficiencies of the processes. This review focuses on the unwanted production of oxygen gas, which decreases the charge yield by up to 5%. Understanding the factors that control the rate of oxygen production requires understanding of both chemical reactions occurring in the electrolyte, as well as surface reactions occurring on the anodes. The dominant anode material used in chlorate and chlor-alkali production is the dimensionally stable anode (DSA), Ti coated by a mixed oxide of RuO2 and TiO2. Although the selectivity for chlorine evolution on DSA is high, the fundamental reasons for this high selectivity are just now becoming elucidated. This review summarizes the research, since the early 1900s until today, concerning the selectivity between chlorine and oxygen evolution in chlorate and chlor-alkali production. It covers experimental as well as theoretical studies and highlights the relationships between process conditions, electrolyte composition, the material properties of the anode, and the selectivity for oxygen formation.

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Section: Selectivity For Oxygen and Chlorine Evolution In Chlor-alkal...mentioning

confidence: 99%

Selectivity between Oxygen and Chlorine Evolution in the Chlor-Alkali and Chlorate Processes

2016

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“…The OER (U 0 = 1.23 V vs RHE, reversible hydrogen electrode) is thermodynamically preferred over the CER (U 0 = 1.36 V vs SHE, standard hydrogen electrode), but the CER is kinetically preferred over the OER: while the CER is a facile 2-electron process, the OER is a sluggish 4-electron process. [16] Therefore, it has been found that the electrocatalysts exhibited higher CER Faraday efficiency at acidic pH, [17] high chloride concentration [18] or high ionic strength. [19] (iii) In recent years, non-noble metal oxides were mixed into CER electrocatalysts to replace noble metal oxides partially [20] or completely.…”

Section: Introductionmentioning

confidence: 99%

Neodymium‐Doped IrO₂ Electrocatalysts Supported on Titanium Plates for Enhanced Chlorine Evolution Reaction Performance

Feng

et al. 2021

ChemElectroChem

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The chlorine evolution reaction (CER) is extensively used in disinfection, chlorine products, and water treatment. However, CER catalysts based on noble metals are expensive, limiting their industrial application. For the purpose of enhancing the CER performance with low usage of Ir, Nd-doped IrO 2 electrocatalysts supported on Ti plates were fabricated by using the sol-gel method. The optimal Ti/Ir 0.8 Nd 0.2 O x electrode exhibited excellent CER performance with a low potential of 1.52 V vs. RHE at 100 mA cm À 2 and a great stability of over 210 h in 5 M NaCl solution. Notably, the mass activity of Ti/Ir 0.8 Nd 0.2 O x (96.5 A g Ir À 1 at 1.5 V vs RHE) was twice as high as that of Ti/IrO 2 , which was the highest among noble metal electrodes reported. Density functional theory calculations indicated that the doping of Nd could clearly decrease the loss of Gibbs free energy for the rate-determining step (desorption of chlorine).

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“…RuO 2 deposited on the Ti is the state-of-the-art catalyst regarding chloride oxidation, owing to various properties: low oxygen/metal fraction and binding energy, high positive surface charge, and reactivity. , Although several dimensionally stable anodes (DSA) have been synthesized using this phase, − the Sb 2 O 3 -doped Ti/RuO 2 –ZrO 2 electrode has become a reference for active chlorine generation. ,, ZrO 2 incorporation increases and spreads the catalytic active sites, whereas Sb 2 O 3 enhances electronic conductivity, stability, and service life . The synthesis of this electrocatalyst via the Pechini method also benefits from a low content of Ru and Zr on the Ti surface, enabling its scale-up for industrial levels.…”

Section: Introductionmentioning

confidence: 99%

Heterogeneous Model To Distinguish the Activity of Electrogenerated Chlorine Species from Soluble Chlorine in an Electrochemical Reactor

Palma‐Goyes

Rivera

Vazquez‐Arenas

2019

Ind. Eng. Chem. Res.

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The formation of active chlorine species on dimensionally stable anodes (DSA) has been used for the treatment of recalcitrant organic compounds contained in wastewater, whereby the present study develops a heterogeneous model thoroughly describing the surface electrochemistry of this mechanism arising in a FM01-LC reactor on Sb2O3-doped Ti/RuO2–ZrO2 anodes. The model accounts for fluid mechanics, mass transport, and kinetics of electrogenerated active chlorine according to the predominance (i.e., HClO species), being able to describe variations in current density and inlet flow rates. These results are compared against a classical homogeneous model to stand out the impacts of adsorbed chloride species and particularly remark deviations in concentration, current efficiency, and pH from experimental data. Experimental HClO concentration, current efficiency, and pH are substantially better simulated by the heterogeneous mechanism, denoting the role of adsorbed chlorine species during chloride oxidation on DSA.

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Physicochemical properties of RuO2 and IrO2 electrodes affecting chlorine evolutions

Cited by 68 publications

References 31 publications

Selectivity between Oxygen and Chlorine Evolution in the Chlor-Alkali and Chlorate Processes

Selectivity between Oxygen and Chlorine Evolution in the Chlor-Alkali and Chlorate Processes

Neodymium‐Doped IrO₂ Electrocatalysts Supported on Titanium Plates for Enhanced Chlorine Evolution Reaction Performance

Heterogeneous Model To Distinguish the Activity of Electrogenerated Chlorine Species from Soluble Chlorine in an Electrochemical Reactor

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Physicochemical properties of RuO2 and IrO2 electrodes affecting chlorine evolutions

Cited by 68 publications

References 31 publications

Selectivity between Oxygen and Chlorine Evolution in the Chlor-Alkali and Chlorate Processes

Selectivity between Oxygen and Chlorine Evolution in the Chlor-Alkali and Chlorate Processes

Neodymium‐Doped IrO2 Electrocatalysts Supported on Titanium Plates for Enhanced Chlorine Evolution Reaction Performance

Heterogeneous Model To Distinguish the Activity of Electrogenerated Chlorine Species from Soluble Chlorine in an Electrochemical Reactor

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Neodymium‐Doped IrO₂ Electrocatalysts Supported on Titanium Plates for Enhanced Chlorine Evolution Reaction Performance