1. Temperature-Dependent Kinetic Studies of the Chlorine Evolution Reaction over RuO2(110) Model Electrodes
- Author
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Herbert Over, Iman Sohrabnejad-Eskan, Andrey Goryachev, Emiel J. M. Hensen, Jan P. Hofmann, Kai S. Exner, Ludwig A. Kibler, and Inorganic Materials & Catalysis
- Subjects
Inorganic chemistry ,RuO ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Activation energy ,010402 general chemistry ,Electrochemistry ,Kinetic energy ,01 natural sciences ,Catalysis ,law.invention ,chlorine evolution reaction (CER) ,law ,Chlorine ,oxygen evolution reaction (OER) ,Electrolysis ,chlor-alkali electrolysis ,Chemistry ,selectivity ,Oxygen evolution ,General Chemistry ,apparent free activation energy ,Chronoamperometry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,0210 nano-technology - Abstract
Ultrathin single-crystalline RuO 2(110) films supported on Ru(0001) are employed as model electrodes to extract kinetic information about the industrially important chlorine evolution reaction (CER) in a 5M concentrated NaCl solution under well-defined electrochemical conditions and variable temperatures. A combination of chronoamperometry (CA) and online electrochemical mass spectrometry (OLEMS) experiments provides insight into the selectivity issue: At pH = 0.9, the CER dominates over oxygen evolution, whereas at pH = 3.5, oxygen evolution and other parasitic side reactions contribute mostly to the total current density. From temperature-dependent CA data for pH = 0.9, we determine the apparent free activation energy of the CER over RuO 2(110) to be 0.91 eV, which compares reasonably well with the theoretical value of 0.79 eV derived from first-principles microkinetics. The experimentally determined apparent free activation energy of 0.91 eV is considered as a benchmark for assessing future improved theoretical modeling from first principles.
- Published
- 2017
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