Kinetic study of the formation of oxygen vacancy on lanthanum manganite electrodes
- Chinese Academy of Sciences, Dalian (China). Dalian Inst. of Chemical Physics
Strontium doped lanthanum manganite (LSM) has been considered one of the most promising cathode materials for solid oxide fuel cells (SOFC). The electrochemical reduction of oxygen on lanthanum manganite (LSM) electrodes has been investigated by cyclic voltammetry, alternating current (ac) impedance, and, in particular, potential step. An emphasis was given to the study of the kinetics of the formation of oxygen vacancy, which is shown to be the main cause for the reversed hysteresis in cyclic voltammograms and for the increase in the electrochemical activity of oxygen reduction on the cathodically polarized LSM electrode observed in both ac impedance and in potential step experiments. The potential step experiments show that the oxygen vacancy concentration increases exponentially with time when the LSM is under a cathodic polarization. In the present study, the rate controlling step for the formation of oxygen vacancies is the oxygen vacancy generation step. The cathodic current rising from the reaction on oxygen vacancies can make a significant contribution to the total reduction current.
- Sponsoring Organization:
- National Science Foundation, Washington, DC (United States)
- OSTI ID:
- 599884
- Journal Information:
- Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 2 Vol. 145; ISSN 0013-4651; ISSN JESOAN
- Country of Publication:
- United States
- Language:
- English
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