Reactivation of chromia poisoned oxygen exchange kinetics in mixed conducting solid oxide fuel cell electrodes by serial infiltration of lithia

Abstract

Solid oxide fuel cells have the potential to render the conversion from fuel to electrical energy more efficienct while lowering emissions. The technology, however, suffers from performance degradation due to cathode poisoning by chromia from metal interconnects. We confirm the deleterious impact of chromia on the performance of the model mixed conducting cathode material Pr0.1Ce0.9O2−δ by examining the oxygen exchange coefficient (kchem) via electrical conductivity relaxation measurements, and the area-specific resistance (ASR) by electrochemical impedance spectroscopy. Liquid Cr-infiltration decreases kchem 20-fold and the oxygen exchange component of ASR increases 20-fold while maintaining the same activation energy. We then demonstrate the ability to not only recover initial kchem and ASR values, but improve properties above those exhibited by the pristine specimen through subsequent Li-infiltration, leading to enhancement of kchem by more than three orders of magnitude and reduction in oxygen exchange component of the ASR by over a factor 100. We attribute these dramatic changes to the depletion of electrons induced by the acidic Cr-infiltrant on the Pr0.1Ce0.9O2−δ surface and the recovery to accumulation of electrons from the basic Li-infiltrant. These results point to acidity as a key descriptor in addressing the long-standing challenge of reactive surface poisoning in applications reliant on rapid oxygen exchange and recovery behavior. The ability to achieve remarkable levels of recovery of electrocatalytic surfaces by controlling the relative acidity of surface species is demonstrated for the first time.

Graphical abstract: Reactivation of chromia poisoned oxygen exchange kinetics in mixed conducting solid oxide fuel cell electrodes by serial infiltration of lithia

Supplementary files

Article information

Article type
Communication
Submitted
22 Dec 2021
Accepted
09 Aug 2022
First published
11 Aug 2022
This article is Open Access
Creative Commons BY-NC license

Energy Environ. Sci., 2022, Advance Article

Reactivation of chromia poisoned oxygen exchange kinetics in mixed conducting solid oxide fuel cell electrodes by serial infiltration of lithia

H. G. Seo, A. Staerz, D. S. Kim, D. Klotz, C. Nicollet, M. Xu, J. M. LeBeau and H. L. Tuller, Energy Environ. Sci., 2022, Advance Article , DOI: 10.1039/D1EE03975J

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements