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dc.contributor.author
Steinfeld, Aldo
dc.contributor.author
Ezbiri, Miriam
dc.contributor.author
Takacs, Michael
dc.contributor.author
Theiler, David
dc.contributor.author
Michalsky, Ronald
dc.contributor.author
Steinfeld, Aldo
dc.date.accessioned
2023-07-20T07:52:43Z
dc.date.available
2017-06-12T19:08:26Z
dc.date.available
2023-07-20T07:52:43Z
dc.date.issued
2017-02-28
dc.identifier.issn
2050-7488
dc.identifier.issn
2050-7496
dc.identifier.other
10.1039/C6TA06644E
en_US
dc.identifier.uri
http://hdl.handle.net/20.500.11850/127012
dc.identifier.doi
10.3929/ethz-b-000127012
dc.description.abstract
Nonstoichiometric metal oxides with variable valence are attractive redox materials for thermochemical and electrochemical fuel processing. To guide the design of advanced redox materials for solar-driven splitting of CO2 and/or H2O to produce CO and/or H2 (syngas), we investigate the equilibrium thermodynamics of the LaxSr1−xMnyAl1−yO3−δ perovskite family (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) and La0.6Ca0.4Mn0.8Al0.2O3−δ, and compare them to those of CeO2 as the baseline. Oxygen nonstoichiometry measurements from 1573 to 1773 K and from 0.206 to 180 mbar O2 show a tunable reduction extent, increasing with increasing Sr content. Maximal nonstoichiometry of 0.32 is established with La0.2Sr0.8Mn0.8Al0.2O3−δ at 1773 K and 2.37 mbar O2. As a trend, we find that oxygen capacities are most sensitive to the A-cation composition. Partial molar enthalpy, entropy and Gibbs free energy changes for oxide reduction are extracted from the experimental data using defect models for Mn4+/Mn3+ and Mn3+/Mn2+ redox couples. We find that perovskites exhibit typically decreasing enthalpy changes with increasing nonstoichiometries. This desirable characteristic is most pronounced by La0.6Sr0.4Mn0.4Al0.6O3−δ, rendering it attractive for CO2 and H2O splitting. Generally, perovskites show lower enthalpy and entropy changes than ceria, resulting in more favorable reduction but less favorable oxidation equilibria. The energy penalties due to larger temperature swings and excess oxidants are discussed in particular. Using electronic structure theory, we conclude with a practical methodology estimating thermodynamic activity to rationally design perovskites with variable stoichiometry and valence.
en_US
dc.format
application/pdf
en_US
dc.language.iso
en
en_US
dc.publisher
Royal Society of Chemistry
en_US
dc.rights.uri
http://creativecommons.org/licenses/by-nc/3.0/
dc.title
Tunable thermodynamic activity of LaxSr1-xMnyAl1-yO3-δ (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) perovskites for solar thermochemical fuel synthesis
en_US
dc.type
Journal Article
dc.rights.license
Creative Commons Attribution-NonCommercial 3.0 Unported
dc.date.published
2017-01-23
ethz.journal.title
Journal of Materials Chemistry A
ethz.journal.volume
5
en_US
ethz.journal.issue
8
en_US
ethz.journal.abbreviated
J. Mater. Chem. A
ethz.pages.start
4172
en_US
ethz.pages.end
4182
en_US
ethz.version.deposit
publishedVersion
en_US
ethz.notes
Published online 23 January 2017.
en_US
ethz.grant
Design of perovskite and doped-ceria redox materials for high performance solar thermochemical splitting of H2O and CO2
en_US
ethz.grant
Solar thermochemical production of fuels
en_US
ethz.identifier.wos
ethz.identifier.scopus
ethz.identifier.nebis
010851126
ethz.publication.place
Cambridge
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02130 - Dep. Maschinenbau und Verfahrenstechnik / Dep. of Mechanical and Process Eng.::02668 - Inst. f. Energie- und Verfahrenstechnik / Inst. Energy and Process Engineering::03530 - Steinfeld, Aldo / Steinfeld, Aldo
en_US
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02130 - Dep. Maschinenbau und Verfahrenstechnik / Dep. of Mechanical and Process Eng.::02668 - Inst. f. Energie- und Verfahrenstechnik / Inst. Energy and Process Engineering::03530 - Steinfeld, Aldo / Steinfeld, Aldo
ethz.grant.agreementno
162435
ethz.grant.agreementno
320541
ethz.grant.fundername
SNF
ethz.grant.fundername
EC
ethz.grant.funderDoi
10.13039/501100001711
ethz.grant.funderDoi
10.13039/501100000780
ethz.grant.program
Projekte MINT
ethz.grant.program
FP7
ethz.date.deposited
2017-06-12T19:08:55Z
ethz.source
ECIT
ethz.identifier.importid
imp593655297f77a65396
ethz.ecitpid
pub:189808
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2017-07-12T21:37:28Z
ethz.rosetta.lastUpdated
2024-02-03T01:49:18Z
ethz.rosetta.versionExported
true
ethz.COinS
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