ac Impedance study of the oxygen reduction mechanism on La1−xSrxMnO3 in solid oxide fuel cells

✍ Scribed by M.J.L. Østergård; M. Mogensen

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 634 KB
• Volume: 38
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(93)80334-v

✦ Synopsis

The kinetics of the oxygen reduction reaction at the La O,slSr,,,,MnO,/ZrO,-Y,O, electrode has been studied by ac impedance spectroscopy. The results show that there are three time constants present in the system, each one corresponding to a rate limiting step of the total reaction mechanism. The time constant at high frequencies has been attribute-d to the charge transfer of oxide ions from the interface electrode/electrolyte to oxide ion vacancies in the electrolyte. The two other time constants, at medium frequencies and low frequencies, have been attributed to 0, *-dissociation and diffusion steps, respectively.