Electrochemistry
Online ISSN : 2186-2451
Print ISSN : 1344-3542
ISSN-L : 1344-3542
Articles
Activation/Deactivation Phenomena’s in the Electrochemical Reduction of O2 and NO on La1−xSrxFeO3−δ
K. Kammer HANSEN
Author information
Keywords: Nitric Oxide, Oxygen, LSF
JOURNALS OPEN ACCESS

2020 Volume 88 Issue 3 Pages 146-150

Details
Abstract

Three ferrite based perovskites were investigated as cathodes for the electrochemical reduction of oxygen and nitric oxide, using cone-shaped electrodes and cyclic voltammetry. The ferrites investigated were LaFeO3, La0.85Sr0.15FeO3−δ and La0.5Sr0.5FeO3−δ. Especially the effect of anodic pre-treatment of the electrodes was investigated. It was shown that the ferrite based electrodes are better at reducing nitric oxide than oxygen in the temperature range 200 to 400°C. The ability of the ferrites to reduce oxygen depends mainly on the amount of Fe(III) and oxide anion vacancies, leading to the highest activity towards the reduction of oxygen for the intermediate compound La0.85Sr0.15FeO3−δ in the investigated temperature range. All the electrodes were either activated or de-activated when polarized at 0.4 vs. air, before recording the voltammograms, depending on temperature and gas atmosphere. This was attributed to annihilation of oxide ion vacancies, strontium segregation to the surface of the electrodes and perhaps formation of Fe(IV). The effect of water vapor was also studied. It had a slightly deactivating effect on the activity in the nitric oxide containing atmosphere, the effect being highest at the lowest temperatures.

Information related to the author
© The Author(s) 2020. Published by ECSJ.

This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial Share Alike 4.0 License (CC BY-NC-SA, http://creativecommons.org/licenses/by-nc-sa/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium by share-alike, provided the original work is properly cited. For permission for commercial reuse, please email to the corresponding author. [DOI: 10.5796/electrochemistry.19-00069]
Uploading "PDF file created by publishers" to institutional repositories or public websites is not permitted by the copyright license agreement.
http://creativecommons.org/licenses/by-nc-sa/4.0/
Previous article Next article
feedback
Top