TY - JOUR
T1 - Experimental measurement of overpotential sources during anodic gas evolution in aqueous and molten salt systems
AU - Chmielowiec, Brian
AU - Fujimura, Tatsuki
AU - Otani, Tomohiro
AU - Aoyama, Kiego
AU - Nohira, Toshiyuki
AU - Homma, Takayuki
AU - Fukunaka, Yasuhiro
AU - Allanore, Antoine
N1 - Funding Information:
The authors acknowledge the Japanese Society for the Promotion of Science (JSPS)/NSF for enabling the experimental activities and collaboration between Japan and USA. Funding from the Office of Naval Research ONR (contract N00014-12-1-0521) to support BC is acknowledged.
Publisher Copyright:
© The Author(s) 2019.
PY - 2019
Y1 - 2019
N2 - Current interrupt and galvanostatic EIS techniques were utilized in a complementary fashion to characterize the different sources of overpotential during anodic gas evolution. Room temperature anodic evolution of oxygen at a nickel working electrode in aqueous potassium hydroxide and the high temperature (348°C) anodic evolution of chlorine at a glassy carbon working electrode in molten (LiCl)57.5-(KCl)13.3-(CsCl)29.2 where investigatd. Combining of the two techniques enables to separate the total measured overpotential into its ohmic, charge transfer, and mass transfer components. Potential decay curves indicated that natural convection (due to both bubble evolution and density driven flow) was a major driving force in reestablishing equilibrium conditions at the working electrode surface. During oxygen evolution, charge transfer resistance dominated the total overpotential at low current densities, but as the current density approached ∼100mA/cm2, mass transfer overpotentials and ohmic overpotential became non-negligible. The mass transfer overpotential during chlorine evolution was found to be half that found during oxygen evolution.
AB - Current interrupt and galvanostatic EIS techniques were utilized in a complementary fashion to characterize the different sources of overpotential during anodic gas evolution. Room temperature anodic evolution of oxygen at a nickel working electrode in aqueous potassium hydroxide and the high temperature (348°C) anodic evolution of chlorine at a glassy carbon working electrode in molten (LiCl)57.5-(KCl)13.3-(CsCl)29.2 where investigatd. Combining of the two techniques enables to separate the total measured overpotential into its ohmic, charge transfer, and mass transfer components. Potential decay curves indicated that natural convection (due to both bubble evolution and density driven flow) was a major driving force in reestablishing equilibrium conditions at the working electrode surface. During oxygen evolution, charge transfer resistance dominated the total overpotential at low current densities, but as the current density approached ∼100mA/cm2, mass transfer overpotentials and ohmic overpotential became non-negligible. The mass transfer overpotential during chlorine evolution was found to be half that found during oxygen evolution.
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U2 - 10.1149/2.1001910jes
DO - 10.1149/2.1001910jes
M3 - Article
AN - SCOPUS:85073448315
VL - 166
SP - E323-E329
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
SN - 0013-4651
IS - 10
ER -
