A study on the deactivation of an IrO2–Ta2O5 coated titanium anode

Xu, Likun; Scantlebury, J.D.

doi:10.1016/s0010-938x(03)00108-2

Cited by 109 publications

(92 citation statements)

References 39 publications

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“…The class of thermally prepared oxide electrodes on titanium metal support contains a catalytically active noble metal oxide (IrO 2 or RuO 2 ) stabilized by TiO 2 , ZrO 2 , or Ta 2 O 5 . The most important commercial types are the RuO 2 /TiO 2 and the IrO 2 / Ta 2 O 5 systems used as electrodes in the chlor-alkali industry and for oxygen evolution [3][4][5][6]. Stability and selectivity can be improved by the addition of other components such as SnO 2 and Sb 2 O 5 [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Investigation of RuO2/Ta2O5 thin film evolution by thermogravimetry combined with mass spectrometry

et al. 2005

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Section: Introductionmentioning

confidence: 99%

Investigation of RuO2/Ta2O5 thin film evolution by thermogravimetry combined with mass spectrometry

et al. 2005

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“…[6][7][8][9] Comninellis and Vercesi performed a comprehensive study of nine different binary catalyst coatings.…”

mentioning

confidence: 99%

Calcination Temperature Dependent Catalytic Activity and Stability of IrO₂–Ta₂O₅Anodes for Oxygen Evolution Reaction in Aqueous Sulfate Electrolytes

Haarberg

Sunde

et al. 2017

J. Electrochem. Soc.

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In this work, commercial IrO 2 -Ta 2 O 5 anodes with a certain composition calcined at three different temperatures were investigated. The results show that the calcination temperature has a significant influence on the electrocatalytic activity for the oxygen evolution reaction (OER). This is attributed to the influence of the calcination temperature on the surface microstructure including the crystallinity and the preferred orientation of IrO 2 crystallites of the IrO 2 -Ta 2 O 5 binary oxide formed. The surface morphology of the anodes was revealed as mud-cracks surrounded by flat areas containing several scattered IrO 2 nanocrystallites. The size of these nanocrystallites, which in turn contribute to the electrochemical active surface area, is dependent on calcination temperature. The (101)-surfaces of the IrO 2 were found to have higher catalytic activity than (110) IrO 2 with respect to the OER. The (101) IrO 2 planes were dominating at low or moderate calcination temperatures, whereas the (110) IrO 2 orientation was preferred at the highest calcination temperature. Accelerated lifetime tests of the investigated samples indicate that the (101) IrO 2 is more stable (110) IrO 2 during electrolysis. A moderate temperature is suggested as the best calcination temperature for this type of anode regarding the electrochemical active surface area, electrocatalytic activity and stability for OER in acidic aqueous electrolytes at operating conditions. © The Author Efficient electrowinning (EW) in aqueous sulfate electrolytes depends on fast reaction kinetics, low ohmic resistances and suppression of parasitic and detrimental reactions. The overall cell voltage is determined by the thermodynamic potentials for metal deposition (cathode) and oxygen evolution (anode), in addition to overpotentials and ohmic voltage drops. The sluggish reaction kinetics of the oxygen evolution reaction (OER) in low-pH sulfate electrolytes lead to rather high anode overpotential at industrial relevant current densities, thus being a significant contributor to an increased cell voltage.1 The low pH, moderate temperature and high anode potential in aqueous metal electrowinning limit the anode material selection significantly, as few materials are stable at these operating conditions. Therefore, identifying an efficient anode catalyst to facilitate the OER by lowering the overpotential has been considered an important research field over many decades also in copper EW.2,3 From an industrial perspective, stability and service lifetime of the anodes are just as important as the electrocatalytic activity. Ru oxide catalysts are known to be the most active for OER, 4 but not stable enough for long term operation in the acidic environment.5 IrO 2 is also very active toward OER and significantly more stable than RuO 2 , but also suffers from some degradation during prolonged operation. [6][7][8][9] Comninellis and Vercesi performed a comprehensive study of nine different binary catalyst coatings.10 They reported that the 70 mol% IrO 2 -30 mol% Ta...

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“…Spectra showing two semicircles have often been obtained for DSA electrodes in sodium chloride solutions. [19][20][21]32 These authors attribute the high frequency semicircle to the resistance and the capacitance of the coating while the semicircle at lower frequencies is assigned to the capacitance of the double layer, C dl and the charge transfer resistance, R ct . In the present work, both semicircles should represent faradaic processes since the diameter of both semicircles decreases with an increase in potential.…”

Section: B Polarization Curvesmentioning

confidence: 99%

“…EIS has been employed in kinetic studies of chlorine evolution on platinum [11][12][13] but not on DSA electrodes. It has been used to characterize DSA anodes in low concentration chloride solutions [14][15][16][17][18][19][20][21] at low potentials, 1.05 V vs Ag/AgCl to 1.18 V vs Ag/AgCl, 22,23 which corresponds to current densities up to 10 mA cm −2 . These conditions are far from those used industrially for producing chlorine, where the current densities reach 400 mA cm −2 .…”

Section: Introductionmentioning

confidence: 99%

Electrochemical cell design for the impedance studies of chlorine evolution at DSA® anodes

Silva

Dias

Araújo

et al. 2016

Review of Scientific Instruments

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A new electrochemical cell design suitable for the electrochemical impedance spectroscopy (EIS) studies of chlorine evolution on Dimensionally Stable Anodes (DSA ® ) has been developed. Despite being considered a powerful tool, EIS has rarely been used to study the kinetics of chlorine evolution at DSA anodes. Cell designs in the open literature are unsuitable for the EIS analysis at high DSA anode current densities for chlorine evolution because they allow gas accumulation at the electrode surface. Using the new cell, the impedance spectra of the DSA anode during chlorine evolution at high sodium chloride concentration (5 mol dm −3 NaCl) and high current densities (up to 140 mA cm −2 ) were recorded. Additionally, polarization curves and voltammograms were obtained showing little or no noise. EIS and polarization curves evidence the role of the adsorption step in the chlorine evolution reaction, compatible with the Volmer-Heyrovsky and Volmer-Tafel mechanisms. Published by AIP Publishing. [http://dx

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A study on the deactivation of an IrO2–Ta2O5 coated titanium anode

Cited by 109 publications

References 39 publications

Investigation of RuO2/Ta2O5 thin film evolution by thermogravimetry combined with mass spectrometry

Investigation of RuO2/Ta2O5 thin film evolution by thermogravimetry combined with mass spectrometry

Calcination Temperature Dependent Catalytic Activity and Stability of IrO₂–Ta₂O₅Anodes for Oxygen Evolution Reaction in Aqueous Sulfate Electrolytes

Electrochemical cell design for the impedance studies of chlorine evolution at DSA® anodes

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A study on the deactivation of an IrO2–Ta2O5 coated titanium anode

Cited by 109 publications

References 39 publications

Investigation of RuO2/Ta2O5 thin film evolution by thermogravimetry combined with mass spectrometry

Investigation of RuO2/Ta2O5 thin film evolution by thermogravimetry combined with mass spectrometry

Calcination Temperature Dependent Catalytic Activity and Stability of IrO2–Ta2O5Anodes for Oxygen Evolution Reaction in Aqueous Sulfate Electrolytes

Electrochemical cell design for the impedance studies of chlorine evolution at DSA® anodes

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Calcination Temperature Dependent Catalytic Activity and Stability of IrO₂–Ta₂O₅Anodes for Oxygen Evolution Reaction in Aqueous Sulfate Electrolytes