Oxygen exchange on platinum electrodes in zirconia cells; Location of electrochemical reaction sites

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Journal of the Electrochemical Society; (USA)

DOI:https://doi.org/10.1149/1.2086347· OSTI ID:6817319

Robertson, N L ^[1]; Michaels, J N ^[2]

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1. IBM Research Div., San Jose, CA (USA). Almaden Research Center
2. California Univ., Berkeley, CA (USA). Dept. of Chemical Engineering

Oxygen exchange kinetics on porous platinum electrodes in a zirconia electrochemical cell were measured at 600{degrees}--800{degrees}C in 10{sup {minus} 5}-0.21 atmospheres oxygen. Steady-state polarization and potential-step chronoamperometric experiments were performed. Steady-state current-voltage characteristics exhibited near-exponential behavior at intermediate potentials and approached anodic and cathodic limiting currents at higher overpotentials. At and below 600{degrees}C, the initial decay of the current following anodic and cathodic potential steps was inversely proportional to the square root of time. This Cottrell-type behavior indicates that the charge-transfer step in the mechanism of oxygen exchange occurs at the three-phase boundary where the electrode, electrolyte, and gas-phase intersect.

• OSTI ID: 6817319
• Journal Information: Journal of the Electrochemical Society; (USA), Journal Name: Journal of the Electrochemical Society; (USA) Vol. 137:1; ISSN JESOA; ISSN 0013-4651
• Country of Publication: United States
• Language: English

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