Extraordinary Stability of IrO2(110) Ultrathin Films Supported on TiO2(110) under Cathodic Polarization
(2020) In Journal of Physical Chemistry Letters p.9057-9062- Abstract
Down to a cathodic potentials of -1.20 V versus the reversible hydrogen electrode, the structure of IrO2(110) electrodes supported by TiO2(110) is found to be stable by in situ synchrotron-based X-ray diffraction. Such high cathodic potentials should lead to reduction to metallic Ir (Pourbaix diagram). From the IrO2 lattice parameters, determined during cathodic polarization in a H2SO4 electrolyte solution (pH 0.4), it is estimated that the unit cell volume increases by 1% due likely to proton incorporation, which is supported by the lack of significant swelling of the IrO2(110) film derived from X-ray reflectivity experiments. Ex situ X-ray photoelectron spectroscopy suggests that protons are incorporated into the IrO2(110) lattice... (More)
Down to a cathodic potentials of -1.20 V versus the reversible hydrogen electrode, the structure of IrO2(110) electrodes supported by TiO2(110) is found to be stable by in situ synchrotron-based X-ray diffraction. Such high cathodic potentials should lead to reduction to metallic Ir (Pourbaix diagram). From the IrO2 lattice parameters, determined during cathodic polarization in a H2SO4 electrolyte solution (pH 0.4), it is estimated that the unit cell volume increases by 1% due likely to proton incorporation, which is supported by the lack of significant swelling of the IrO2(110) film derived from X-ray reflectivity experiments. Ex situ X-ray photoelectron spectroscopy suggests that protons are incorporated into the IrO2(110) lattice below -1.0 V, although Ir remains exclusively in the IV+ oxidation state down to -1.20 V. Obviously, further hydrogenation of the lattice oxygen of IrO2(110) toward water is suppressed for kinetic reasons and hints at a rate-determining chemical step that cannot be controlled by the electrode potential.
(Less)
- author
- Weber, Tim ; Vonk, Vedran ; Abb, Marcel J.S. ; Evertsson, Jonas LU ; Sandroni, Martina ; Drnec, Jakub ; Stierle, Andreas ; Lundgren, Edvin LU and Over, Herbert
- organization
- publishing date
- 2020
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Physical Chemistry Letters
- pages
- 6 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:33045835
- scopus:85094664197
- ISSN
- 1948-7185
- DOI
- 10.1021/acs.jpclett.0c02730
- language
- English
- LU publication?
- yes
- id
- 9022d898-25b1-4535-bd8e-c78b44570735
- date added to LUP
- 2020-11-23 10:51:04
- date last changed
- 2024-03-20 19:54:02
@article{9022d898-25b1-4535-bd8e-c78b44570735, abstract = {{<p>Down to a cathodic potentials of -1.20 V versus the reversible hydrogen electrode, the structure of IrO2(110) electrodes supported by TiO2(110) is found to be stable by in situ synchrotron-based X-ray diffraction. Such high cathodic potentials should lead to reduction to metallic Ir (Pourbaix diagram). From the IrO2 lattice parameters, determined during cathodic polarization in a H2SO4 electrolyte solution (pH 0.4), it is estimated that the unit cell volume increases by 1% due likely to proton incorporation, which is supported by the lack of significant swelling of the IrO2(110) film derived from X-ray reflectivity experiments. Ex situ X-ray photoelectron spectroscopy suggests that protons are incorporated into the IrO2(110) lattice below -1.0 V, although Ir remains exclusively in the IV+ oxidation state down to -1.20 V. Obviously, further hydrogenation of the lattice oxygen of IrO2(110) toward water is suppressed for kinetic reasons and hints at a rate-determining chemical step that cannot be controlled by the electrode potential.</p>}}, author = {{Weber, Tim and Vonk, Vedran and Abb, Marcel J.S. and Evertsson, Jonas and Sandroni, Martina and Drnec, Jakub and Stierle, Andreas and Lundgren, Edvin and Over, Herbert}}, issn = {{1948-7185}}, language = {{eng}}, pages = {{9057--9062}}, publisher = {{The American Chemical Society (ACS)}}, series = {{Journal of Physical Chemistry Letters}}, title = {{Extraordinary Stability of IrO<sub>2</sub>(110) Ultrathin Films Supported on TiO<sub>2</sub>(110) under Cathodic Polarization}}, url = {{http://dx.doi.org/10.1021/acs.jpclett.0c02730}}, doi = {{10.1021/acs.jpclett.0c02730}}, year = {{2020}}, }