Tuning Surface Acidity of Mixed Conducting Electrodes: Recovery of Si‐Induced Degradation of Oxygen Exchange Rate and Area Specific Resistance
Name
Advanced Materials - 2022 - Seo - Tuning Surface Acidity of Mixed Conducting Electrodes Recovery of Si‐Induced Degradation.pdf
Description
Published version
Size
2.69 MB
Format
Adobe PDF
Checksum (MD5)
ae7c59933fb43f9c8aac105222a4d427
Author(s)
Seo, Han Gil
Staerz, Anna
Kim, Dennis S
LeBeau, James M
Tuller, Harry L
Date Issued
December 3, 2022
Journal
Advanced Materials
Publisher
Wiley
Citation
Seo, Han Gil, Staerz, Anna, Kim, Dennis S, LeBeau, James M and Tuller, Harry L. 2022. "Tuning Surface Acidity of Mixed Conducting Electrodes: Recovery of Si‐Induced Degradation of Oxygen Exchange Rate and Area Specific Resistance." Advanced Materials.
Version
Final published version
Abstract
Metal oxides are an important class of functional materials, and for many applications, ranging from solid oxide fuel/electrolysis cells, oxygen permeation membranes, and oxygen storage materials to gas sensors (semiconducting and electrolytic) and catalysts, the interaction between the surface and oxygen in the gas phase is central. Ubiquitous Si-impurities are known to impede this interaction, commonly attributed to the formation of glassy blocking layers on the surface. Here, the surface oxygen exchange coefficient (kchem ) is examined for Pr0.1 Ce0.9 O2-δ (PCO), a model mixed ionic electronic conductor, via electrical conductivity relaxation measurements, and the area-specific resistance (ASR) by electrochemical impedance spectroscopy. It is demonstrated that even low silica levels, introduced by infiltration, depress kchem by a factor 4000, while the ASR increases 40-fold and we attribute this to its acidity relative to that of PCO. The ability to fully regenerate the poisoned surface by the subsequent addition of basic Ca- or Li-species is further shown. This ability to not only recover Si-poisoned surfaces by tuning the relative surface acidity of an oxide surface, but subsequently outperform the pre-poisoned response, promises to extend the operating life of materials and devices for which the catalytic oxygen/solid interface reaction is central.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1002/adma.202208182
