Activity and Operational Loss of IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti Anodes During Oxygen Evolution in Acidic Solutions

The oxygen-evolving IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti anode (OEA), primarily used in electrolyzers for plating, metal powder production, electrowinning (EW), and water electrolysis, is analyzed. This study focuses on the distribution of oxygen evoluti...

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Main Authors: Jovana Bošnjaković, Maja Stevanović, Marija Mihailović, Vojin M. Tadić, Jasmina Stevanović, Vladimir Panić, Gavrilo Šekularac
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Metals
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Online Access:https://www.mdpi.com/2075-4701/15/7/721
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author Jovana Bošnjaković
Maja Stevanović
Marija Mihailović
Vojin M. Tadić
Jasmina Stevanović
Vladimir Panić
Gavrilo Šekularac
author_facet Jovana Bošnjaković
Maja Stevanović
Marija Mihailović
Vojin M. Tadić
Jasmina Stevanović
Vladimir Panić
Gavrilo Šekularac
author_sort Jovana Bošnjaković
collection DOAJ
description The oxygen-evolving IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti anode (OEA), primarily used in electrolyzers for plating, metal powder production, electrowinning (EW), and water electrolysis, is analyzed. This study focuses on the distribution of oxygen evolution reaction (OER) activity and the associated operational loss over the randomized OEA texture. The OER activity and its distribution across the IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub> coating surface are key factors that influence EW operational challenges and the lifecycle of OEA in EW processes. To understand the OER activity distribution over the coating’s randomized texture, we performed analyses using anode polarization in acid solution at both low and high (EW operation relevant) overpotentials and electrochemical impedance spectroscopy (EIS) during the OER. These measurements were conducted on anodes in both their as-prepared and deactivated states. The as-prepared anode was deactivated using an accelerated stability test in an acid solution, the EW simulating electrolyte. The obtained data are correlated with fundamental electrochemical properties of OEA, such as structure-related pseudocapacitive responses at open circuit potential in the same operating environment. OER and Ir dissolution kinetics, along with the physicochemical anode state upon deactivation, are clearly characterized based on current and potential dependent charge transfer resistances and associated double layer capacitances obtained by EIS. This approach presents a useful tool for elucidating, and consequently tailoring and predicting, anode OER activity and electrolytic operational stability in industrial electrochemical applications.
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spelling doaj-art-5d9d5ad1953641da8d33eecff81cec962025-08-20T03:32:32ZengMDPI AGMetals2075-47012025-06-0115772110.3390/met15070721Activity and Operational Loss of IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti Anodes During Oxygen Evolution in Acidic SolutionsJovana Bošnjaković0Maja Stevanović1Marija Mihailović2Vojin M. Tadić3Jasmina Stevanović4Vladimir Panić5Gavrilo Šekularac6Institute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, Njegoševa 12, 11000 Belgrade, SerbiaInnovation Center of the Faculty of Technology and Metallurgy, Karnegijeva 4, 11000 Belgrade, SerbiaInstitute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, Njegoševa 12, 11000 Belgrade, SerbiaElectrical Power Supply Company of Serbia, Carice Milice 2, 11000 Belgrade, SerbiaInstitute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, Njegoševa 12, 11000 Belgrade, SerbiaInstitute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, Njegoševa 12, 11000 Belgrade, SerbiaInstitute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, Njegoševa 12, 11000 Belgrade, SerbiaThe oxygen-evolving IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti anode (OEA), primarily used in electrolyzers for plating, metal powder production, electrowinning (EW), and water electrolysis, is analyzed. This study focuses on the distribution of oxygen evolution reaction (OER) activity and the associated operational loss over the randomized OEA texture. The OER activity and its distribution across the IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub> coating surface are key factors that influence EW operational challenges and the lifecycle of OEA in EW processes. To understand the OER activity distribution over the coating’s randomized texture, we performed analyses using anode polarization in acid solution at both low and high (EW operation relevant) overpotentials and electrochemical impedance spectroscopy (EIS) during the OER. These measurements were conducted on anodes in both their as-prepared and deactivated states. The as-prepared anode was deactivated using an accelerated stability test in an acid solution, the EW simulating electrolyte. The obtained data are correlated with fundamental electrochemical properties of OEA, such as structure-related pseudocapacitive responses at open circuit potential in the same operating environment. OER and Ir dissolution kinetics, along with the physicochemical anode state upon deactivation, are clearly characterized based on current and potential dependent charge transfer resistances and associated double layer capacitances obtained by EIS. This approach presents a useful tool for elucidating, and consequently tailoring and predicting, anode OER activity and electrolytic operational stability in industrial electrochemical applications.https://www.mdpi.com/2075-4701/15/7/721IrO<sub>2</sub>-based anodestransition metal oxidesOER catalystsanode coatingsanode lifetimedeactivated anode
spellingShingle Jovana Bošnjaković
Maja Stevanović
Marija Mihailović
Vojin M. Tadić
Jasmina Stevanović
Vladimir Panić
Gavrilo Šekularac
Activity and Operational Loss of IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti Anodes During Oxygen Evolution in Acidic Solutions
Metals
IrO<sub>2</sub>-based anodes
transition metal oxides
OER catalysts
anode coatings
anode lifetime
deactivated anode
title Activity and Operational Loss of IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti Anodes During Oxygen Evolution in Acidic Solutions
title_full Activity and Operational Loss of IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti Anodes During Oxygen Evolution in Acidic Solutions
title_fullStr Activity and Operational Loss of IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti Anodes During Oxygen Evolution in Acidic Solutions
title_full_unstemmed Activity and Operational Loss of IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti Anodes During Oxygen Evolution in Acidic Solutions
title_short Activity and Operational Loss of IrO<sub>2</sub>-Ta<sub>2</sub>O<sub>5</sub>/Ti Anodes During Oxygen Evolution in Acidic Solutions
title_sort activity and operational loss of iro sub 2 sub ta sub 2 sub o sub 5 sub ti anodes during oxygen evolution in acidic solutions
topic IrO<sub>2</sub>-based anodes
transition metal oxides
OER catalysts
anode coatings
anode lifetime
deactivated anode
url https://www.mdpi.com/2075-4701/15/7/721
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