Platinized titanium dioxide electrodes for methanol oxidation and photo-oxidation (Dedicated to 75th birthday of Professor Sergio Trasatti)

  • Svetlozar Ivanov Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences, Sofia 1113
  • Ioanna Mintsouli Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124
  • Jenia Georgieva Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences, Sofia 1113
  • Stephan Armyanov Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences, Sofia 1113
  • Eugenia Valova Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences, Sofia 1113
  • Georgios Kokkinidis Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124
  • Ioannis Poulios Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124
  • Sotiris Sotiropoulos Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124

Abstract

Platinized deposits have been formed on TiO2 particulate films supported on Ti substrates, by means of galvanic replacement of pre-deposited metallic Cu and subsequent immersion of the Cu/TiO2 coatings into a chloroplatinic acid solution. The spontaneous replacement of Cu by Pt results in Pt(Cu)/TiO2/Ti electrodes. Both the platinized and the precursor TiO2/Ti electrodes have been characterized by SEM micro­scopy/EDS spectroscopy, their surface electrochemistry has been assessed by cyclic voltammetry in the dark and their photoelectrochemical properties by photovolta­m­metry under UV illumination. It has been found that, although platinized rutile-rich electrodes exhibit typical Pt surface electrochemistry, the anatase-rich electrodes show only traces of oxide formation and stripping. The latter has been translated to a suppression of methanol oxidation at anatase-rich electrodes. On the contrary, methanol oxidation at platinized rutile-rich electrodes occurs at significant rates and can be further enhanced upon UV illumination, as a result of Pt and TiO2 synergism in the photoelectrochemical oxidation of methanol.

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Published
10-11-2012
Section
Electrochemical Engineering