Electrical conductivity relaxation of Sr2Fe1.5Mo0.5O6−δ–Sm0.2Ce0.8O1.9 dual-phase composites

Yunlong Wang, Bobing Hu, Zhuoying Zhu, Henricus J.M. Bouwmeester, Changrong Xia

Research output: Contribution to journalArticleAcademicpeer-review

22 Citations (Scopus)

Abstract

The oxygen incorporation kinetics of Sr2Fe1.5Mo0.5O6 d–Sm0.2Ce0.8O1.9 (SFM–SDC) dual-phase composites has been investigated, at 750 C, as a function of SDC phase volume fraction using electrical conductivity relaxation. It is shown that the oxygen re-equilibration kinetics in the range of oxygen partial pressure (pO2) from 0.01 to 1 atm is limited by the surface exchange rate. The effective surface exchange coefficient of the composites is found to increase profoundly upon increasing the phase volume fraction of the oxide electrolyte phase SDC. The results are interpreted to reflect the synergistic oxygen incorporation at the SFM–SDC–gas triple phase boundaries (TPBs), which occurs in addition to the direct incorporation via the surface of the perovskite mixed conductor SFM. Already at a SDC phase volume fraction of 0.105, the uptake of oxygen via the synergistic TPB route (referred to as route III), following a step change in the surrounding pO2, comprises more than 75% of the overall uptake of oxygen by the composite. It is further concluded that under the conditions of the experiments the twophase SFM–SDC boundaries allow for a facile exchange of oxygen ions between both involved phases.
Original languageEnglish
Pages (from-to)136-143
JournalJournal of materials chemistry. A
Volume2
Issue number1
DOIs
Publication statusPublished - 2014

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Oxygen
Composite materials
Volume fraction
Phase boundaries
Kinetics
Electric Conductivity
Partial pressure
Perovskite
Oxides
Electrolytes
Ion exchange
Ions
Experiments

Keywords

  • IR-87839
  • METIS-298915

Cite this

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title = "Electrical conductivity relaxation of Sr2Fe1.5Mo0.5O6−δ–Sm0.2Ce0.8O1.9 dual-phase composites",
abstract = "The oxygen incorporation kinetics of Sr2Fe1.5Mo0.5O6 d–Sm0.2Ce0.8O1.9 (SFM–SDC) dual-phase composites has been investigated, at 750 C, as a function of SDC phase volume fraction using electrical conductivity relaxation. It is shown that the oxygen re-equilibration kinetics in the range of oxygen partial pressure (pO2) from 0.01 to 1 atm is limited by the surface exchange rate. The effective surface exchange coefficient of the composites is found to increase profoundly upon increasing the phase volume fraction of the oxide electrolyte phase SDC. The results are interpreted to reflect the synergistic oxygen incorporation at the SFM–SDC–gas triple phase boundaries (TPBs), which occurs in addition to the direct incorporation via the surface of the perovskite mixed conductor SFM. Already at a SDC phase volume fraction of 0.105, the uptake of oxygen via the synergistic TPB route (referred to as route III), following a step change in the surrounding pO2, comprises more than 75{\%} of the overall uptake of oxygen by the composite. It is further concluded that under the conditions of the experiments the twophase SFM–SDC boundaries allow for a facile exchange of oxygen ions between both involved phases.",
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Electrical conductivity relaxation of Sr2Fe1.5Mo0.5O6−δ–Sm0.2Ce0.8O1.9 dual-phase composites. / Wang, Yunlong; Hu, Bobing; Zhu, Zhuoying; Bouwmeester, Henricus J.M.; Xia, Changrong.

In: Journal of materials chemistry. A, Vol. 2, No. 1, 2014, p. 136-143.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Electrical conductivity relaxation of Sr2Fe1.5Mo0.5O6−δ–Sm0.2Ce0.8O1.9 dual-phase composites

AU - Wang, Yunlong

AU - Hu, Bobing

AU - Zhu, Zhuoying

AU - Bouwmeester, Henricus J.M.

AU - Xia, Changrong

PY - 2014

Y1 - 2014

N2 - The oxygen incorporation kinetics of Sr2Fe1.5Mo0.5O6 d–Sm0.2Ce0.8O1.9 (SFM–SDC) dual-phase composites has been investigated, at 750 C, as a function of SDC phase volume fraction using electrical conductivity relaxation. It is shown that the oxygen re-equilibration kinetics in the range of oxygen partial pressure (pO2) from 0.01 to 1 atm is limited by the surface exchange rate. The effective surface exchange coefficient of the composites is found to increase profoundly upon increasing the phase volume fraction of the oxide electrolyte phase SDC. The results are interpreted to reflect the synergistic oxygen incorporation at the SFM–SDC–gas triple phase boundaries (TPBs), which occurs in addition to the direct incorporation via the surface of the perovskite mixed conductor SFM. Already at a SDC phase volume fraction of 0.105, the uptake of oxygen via the synergistic TPB route (referred to as route III), following a step change in the surrounding pO2, comprises more than 75% of the overall uptake of oxygen by the composite. It is further concluded that under the conditions of the experiments the twophase SFM–SDC boundaries allow for a facile exchange of oxygen ions between both involved phases.

AB - The oxygen incorporation kinetics of Sr2Fe1.5Mo0.5O6 d–Sm0.2Ce0.8O1.9 (SFM–SDC) dual-phase composites has been investigated, at 750 C, as a function of SDC phase volume fraction using electrical conductivity relaxation. It is shown that the oxygen re-equilibration kinetics in the range of oxygen partial pressure (pO2) from 0.01 to 1 atm is limited by the surface exchange rate. The effective surface exchange coefficient of the composites is found to increase profoundly upon increasing the phase volume fraction of the oxide electrolyte phase SDC. The results are interpreted to reflect the synergistic oxygen incorporation at the SFM–SDC–gas triple phase boundaries (TPBs), which occurs in addition to the direct incorporation via the surface of the perovskite mixed conductor SFM. Already at a SDC phase volume fraction of 0.105, the uptake of oxygen via the synergistic TPB route (referred to as route III), following a step change in the surrounding pO2, comprises more than 75% of the overall uptake of oxygen by the composite. It is further concluded that under the conditions of the experiments the twophase SFM–SDC boundaries allow for a facile exchange of oxygen ions between both involved phases.

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KW - METIS-298915

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DO - 10.1039/c3ta12787g

M3 - Article

VL - 2

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EP - 143

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