Potential-Induced Pitting Corrosion of an IrO2(110)-RuO2(110)/Ru(0001) Model Electrode under Oxygen Evolution Reaction Conditions

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Abstract

Sophisticated IrO2(110)-based model electrodes are prepared by deposition of a 10 nm thick single-crystalline IrO2(110) layer supported on a structure-directing RuO2(110)/Ru(0001) template, exposing a regular array of mesoscopic rooflike structures. With this model electrode together with the dedicated in situ synchrotron based techniques (SXRD, XRR) and ex situ characterization techniques (SEM, ToF-SIMS, XPS), the corrosion process of IrO2(110) in an acidic environment (pH 0.4) is studied on different length scales. Potential-induced pitting corrosion starts at 1.48 V vs SHE and is initiated at so-called surface grain boundaries, where three rotational domains of IrO2(110) meet. The most surprising result is, however, that even when the electrode potential is increased to 1.94 V vs SHE 60-70% of the IrO2 film still stays intact down to the mesoscale and atomic scale and no uniform thinning of the IrO2(110) layer is encountered. Neither flat IrO2(110) terraces nor single steps are attacked. Ultrathin single-crystalline IrO2(110) layers seem to be much more stable to anodic corrosion than hitherto expected.

Detaljer

Författare
  • Tim Weber
  • Johannes Pfrommer
  • Marcel J.S. Abb
  • Benjamin Herd
  • Omeir Khalid
  • Marcus Rohnke
  • Pirmin H. Lakner
  • Jonas Evertsson
  • Sergey Volkov
  • Florian Bertram
  • Raja Znaiguia
  • Francesco Carla
  • Vedran Vonk
  • Edvin Lundgren
  • Andreas Stierle
  • Herbert Over
Enheter & grupper
Externa organisationer
  • Justus Liebig University Giessen
  • German Electron Synchrotron (DESY)
  • University of Hamburg
  • European Synchrotron Radiation Facility
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Korrosionsteknik

Nyckelord

Originalspråkengelska
Sidor (från-till)6530-6539
Antal sidor10
TidskriftACS Catalysis
Volym9
Utgivningsnummer7
StatusPublished - 2019 jun 12
PublikationskategoriForskning
Peer review utfördJa