Bi-Functional Oxygen Electrocatalysts for Reversible Solid Oxide Cells: The Influence of A-Site Non-stoichiometry on the System (La or Ba)0.6-xSr0.4Co0.8Fe0.2O3−δ
Selective tailoring of stoichiometry in perovskite oxide generates excellent electrocatalytic activity toward redox reaction of oxygen [oxygen evolution reaction (OER) and oxygen reduction reaction (ORR)]. The redox reaction of oxygen is kinetically sluggish (spin relaxed reaction) and is the rate-l...
| Autores: | , , , , , , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/406447 |
| Acceso en línea: | http://hdl.handle.net/10261/406447 https://www.scopus.com/inward/record.uri?eid=2-s2.0-105005768938&doi=10.1021%2facsaem.5c00803&partnerID=40&md5=65629196be936b3aa9b4d5d072de0f1c |
| Access Level: | acceso abierto |
| Palabra clave: | A-site non-stoichiometry Bifunctional electrocatalyst Oxygen defects Oxygen evolution reaction (OER) Oxygen reduction reaction (ORR) Solid oxide cell (SOC) |
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| dc.title.none.fl_str_mv |
Bi-Functional Oxygen Electrocatalysts for Reversible Solid Oxide Cells: The Influence of A-Site Non-stoichiometry on the System (La or Ba)0.6-xSr0.4Co0.8Fe0.2O3−δ |
| title |
Bi-Functional Oxygen Electrocatalysts for Reversible Solid Oxide Cells: The Influence of A-Site Non-stoichiometry on the System (La or Ba)0.6-xSr0.4Co0.8Fe0.2O3−δ |
| spellingShingle |
Bi-Functional Oxygen Electrocatalysts for Reversible Solid Oxide Cells: The Influence of A-Site Non-stoichiometry on the System (La or Ba)0.6-xSr0.4Co0.8Fe0.2O3−δ Dey, S. A-site non-stoichiometry Bifunctional electrocatalyst Oxygen defects Oxygen evolution reaction (OER) Oxygen reduction reaction (ORR) Solid oxide cell (SOC) |
| title_short |
Bi-Functional Oxygen Electrocatalysts for Reversible Solid Oxide Cells: The Influence of A-Site Non-stoichiometry on the System (La or Ba)0.6-xSr0.4Co0.8Fe0.2O3−δ |
| title_full |
Bi-Functional Oxygen Electrocatalysts for Reversible Solid Oxide Cells: The Influence of A-Site Non-stoichiometry on the System (La or Ba)0.6-xSr0.4Co0.8Fe0.2O3−δ |
| title_fullStr |
Bi-Functional Oxygen Electrocatalysts for Reversible Solid Oxide Cells: The Influence of A-Site Non-stoichiometry on the System (La or Ba)0.6-xSr0.4Co0.8Fe0.2O3−δ |
| title_full_unstemmed |
Bi-Functional Oxygen Electrocatalysts for Reversible Solid Oxide Cells: The Influence of A-Site Non-stoichiometry on the System (La or Ba)0.6-xSr0.4Co0.8Fe0.2O3−δ |
| title_sort |
Bi-Functional Oxygen Electrocatalysts for Reversible Solid Oxide Cells: The Influence of A-Site Non-stoichiometry on the System (La or Ba)0.6-xSr0.4Co0.8Fe0.2O3−δ |
| dc.creator.none.fl_str_mv |
Dey, S. Saravanan, R. Sethurajaperumal, A. Bal, R. Mather, Glenn C. Ganesh, G. Varrla, E. Puranik, A. Nowicki, K. Mukhopadhyay, M. Allu, A.R. Mukhopadhyay, J. |
| author |
Dey, S. |
| author_facet |
Dey, S. Saravanan, R. Sethurajaperumal, A. Bal, R. Mather, Glenn C. Ganesh, G. Varrla, E. Puranik, A. Nowicki, K. Mukhopadhyay, M. Allu, A.R. Mukhopadhyay, J. |
| author_role |
author |
| author2 |
Saravanan, R. Sethurajaperumal, A. Bal, R. Mather, Glenn C. Ganesh, G. Varrla, E. Puranik, A. Nowicki, K. Mukhopadhyay, M. Allu, A.R. Mukhopadhyay, J. |
| author2_role |
author author author author author author author author author author author |
| dc.contributor.none.fl_str_mv |
Council of Science and Technology UP (India) Agencia Estatal de Investigación (España) Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72] |
| dc.subject.none.fl_str_mv |
A-site non-stoichiometry Bifunctional electrocatalyst Oxygen defects Oxygen evolution reaction (OER) Oxygen reduction reaction (ORR) Solid oxide cell (SOC) |
| topic |
A-site non-stoichiometry Bifunctional electrocatalyst Oxygen defects Oxygen evolution reaction (OER) Oxygen reduction reaction (ORR) Solid oxide cell (SOC) |
| description |
Selective tailoring of stoichiometry in perovskite oxide generates excellent electrocatalytic activity toward redox reaction of oxygen [oxygen evolution reaction (OER) and oxygen reduction reaction (ORR)]. The redox reaction of oxygen is kinetically sluggish (spin relaxed reaction) and is the rate-limiting step for solid oxide cells (SOCs). We have reported that introducing non-stoichiometry at the A-site in A0.6-xSr0.4Co0.8Fe0.2O3−δ imparts a bifunctional electrocatalyst for OER and ORR with excellent performance in fuel cell (FC) and electrolyzer cell (EC) mode. Two compositions, Ba0.6Sr0.4Co0.8Fe0.2O3−δ (BSCF-6482) and La0.6Sr0.4Co0.8Fe0.2O3−δ (LSCF-6482), are designed by varying the non-stoichiometry from 0.6 to 0.52 for Ba and La, respectively. X-ray photoelectron spectroscopy (XP spectroscopy), iodometric estimation, and O2-temperature-programmed desorption (O2-TPD) reveal that Ba0.54Sr0.4Co0.8Fe0.2O3−δ (BS-54) promotes oxygen surface exchange (higher β-oxygen population) and La0.54Sr0.4Co0.8Fe0.2O3−δ (LS-54) accelerates α-oxygen desorption (charge-transfer reaction). A study of the distribution of relaxation time (DRT) using EIS (electrochemical impedance spectroscopy) on cell configuration LS-54 (or BS-54)/GDC-LS-54 (or BS-54)//GDC//Pt@800 °C reveals that LS-54 has minimum electrode polarization (comprising dual processes of charge transfer and oxygen surface exchange) at both +0.8 V (OER) and −0.8 V (ORR), which resonates at 103-104 Hz. It is corroborated that α-oxygen is associated with the charge-transfer process and controls the ORR, whereas the OER is assisted by oxygen surface exchange, primarily linked with β-oxygen. Inclusion of non-stoichiometry at the A-site promotes oxygen-vacancy formation and stabilizes a lower valence state for the B-site cations. The rate-controlling steps for the OER and ORR thereby alter in LS-54 and BS-54 compared to LSCF/BSCF-6482. Electrochemical measurements show superior reversible solid oxide cell (SOC) performance of LS-54 having a current density (CD) of 1.27 A cm-2 @1.5 V and 0.66 A cm-2@0.5 V for a cell with dimensions as large as 5 cm × 5 cm. A similar cell operated with a CD of 1.0 A cm2 under standalone mode of operation in FC. This work proposes a novel strategy to demonstrate A-site non-stoichiometric La0.54Sr0.4Co0.8Fe0.2O3−δ to be a superior bifunctional electrocatalyst for both OER and ORR for SOCs. © 2025 American Chemical Society. |
| publishDate |
2025 |
| dc.date.none.fl_str_mv |
2025 2025 2025 |
| dc.type.none.fl_str_mv |
info:eu-repo/semantics/article http://purl.org/coar/resource_type/c_6501 Postprint info:eu-repo/semantics/acceptedVersion |
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article |
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acceptedVersion |
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http://hdl.handle.net/10261/406447 https://www.scopus.com/inward/record.uri?eid=2-s2.0-105005768938&doi=10.1021%2facsaem.5c00803&partnerID=40&md5=65629196be936b3aa9b4d5d072de0f1c |
| url |
http://hdl.handle.net/10261/406447 https://www.scopus.com/inward/record.uri?eid=2-s2.0-105005768938&doi=10.1021%2facsaem.5c00803&partnerID=40&md5=65629196be936b3aa9b4d5d072de0f1c |
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#PLACEHOLDER_PARENT_METADATA_VALUE# info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2021-2023/PID2021-123308OB-I00 ACS Applied Energy Materials https://doi.org/10.1021/acsaem.5c00803 Sí |
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info:eu-repo/semantics/openAccess |
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openAccess |
| dc.publisher.none.fl_str_mv |
American Chemical Society |
| publisher.none.fl_str_mv |
American Chemical Society |
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reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC instname:Consejo Superior de Investigaciones Científicas (CSIC) |
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Consejo Superior de Investigaciones Científicas (CSIC) |
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DIGITAL.CSIC. Repositorio Institucional del CSIC |
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DIGITAL.CSIC. Repositorio Institucional del CSIC |
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1869411605290156032 |
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Bi-Functional Oxygen Electrocatalysts for Reversible Solid Oxide Cells: The Influence of A-Site Non-stoichiometry on the System (La or Ba)0.6-xSr0.4Co0.8Fe0.2O3−δDey, S.Saravanan, R.Sethurajaperumal, A.Bal, R.Mather, Glenn C.Ganesh, G.Varrla, E.Puranik, A.Nowicki, K.Mukhopadhyay, M.Allu, A.R.Mukhopadhyay, J.A-site non-stoichiometryBifunctional electrocatalystOxygen defectsOxygen evolution reaction (OER)Oxygen reduction reaction (ORR)Solid oxide cell (SOC)Selective tailoring of stoichiometry in perovskite oxide generates excellent electrocatalytic activity toward redox reaction of oxygen [oxygen evolution reaction (OER) and oxygen reduction reaction (ORR)]. The redox reaction of oxygen is kinetically sluggish (spin relaxed reaction) and is the rate-limiting step for solid oxide cells (SOCs). We have reported that introducing non-stoichiometry at the A-site in A0.6-xSr0.4Co0.8Fe0.2O3−δ imparts a bifunctional electrocatalyst for OER and ORR with excellent performance in fuel cell (FC) and electrolyzer cell (EC) mode. Two compositions, Ba0.6Sr0.4Co0.8Fe0.2O3−δ (BSCF-6482) and La0.6Sr0.4Co0.8Fe0.2O3−δ (LSCF-6482), are designed by varying the non-stoichiometry from 0.6 to 0.52 for Ba and La, respectively. X-ray photoelectron spectroscopy (XP spectroscopy), iodometric estimation, and O2-temperature-programmed desorption (O2-TPD) reveal that Ba0.54Sr0.4Co0.8Fe0.2O3−δ (BS-54) promotes oxygen surface exchange (higher β-oxygen population) and La0.54Sr0.4Co0.8Fe0.2O3−δ (LS-54) accelerates α-oxygen desorption (charge-transfer reaction). A study of the distribution of relaxation time (DRT) using EIS (electrochemical impedance spectroscopy) on cell configuration LS-54 (or BS-54)/GDC-LS-54 (or BS-54)//GDC//Pt@800 °C reveals that LS-54 has minimum electrode polarization (comprising dual processes of charge transfer and oxygen surface exchange) at both +0.8 V (OER) and −0.8 V (ORR), which resonates at 103-104 Hz. It is corroborated that α-oxygen is associated with the charge-transfer process and controls the ORR, whereas the OER is assisted by oxygen surface exchange, primarily linked with β-oxygen. Inclusion of non-stoichiometry at the A-site promotes oxygen-vacancy formation and stabilizes a lower valence state for the B-site cations. The rate-controlling steps for the OER and ORR thereby alter in LS-54 and BS-54 compared to LSCF/BSCF-6482. Electrochemical measurements show superior reversible solid oxide cell (SOC) performance of LS-54 having a current density (CD) of 1.27 A cm-2 @1.5 V and 0.66 A cm-2@0.5 V for a cell with dimensions as large as 5 cm × 5 cm. A similar cell operated with a CD of 1.0 A cm2 under standalone mode of operation in FC. This work proposes a novel strategy to demonstrate A-site non-stoichiometric La0.54Sr0.4Co0.8Fe0.2O3−δ to be a superior bifunctional electrocatalyst for both OER and ORR for SOCs. © 2025 American Chemical Society.The authors acknowledge all Institutions & Universities involved herein. The funding for the presented research has been supported by the Council of Scientific and Industrial Research (CSIR), Govt. of India, under “CSIR Hydrogen Technology (H2T)-Mission Program” [CGCRI/BDPD/Project-OM-23 −24/32] and Centre for High Technology, Oil Industries Development Board MoP & NG [CGCRI/BDPD/Project-OM-22-23/04]. G.C.M. acknowledges the project PID2021-123308OB-I00, funded by MCIN/AEI/10.13039/501100011033 in Spain and “ERDF A way of making Europe” by the European Union.The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsaem.5c00803.Peer reviewedAmerican Chemical SocietyCouncil of Science and Technology UP (India)Agencia Estatal de Investigación (España)Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]202520252025info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Postprintinfo:eu-repo/semantics/acceptedVersionhttp://hdl.handle.net/10261/406447https://www.scopus.com/inward/record.uri?eid=2-s2.0-105005768938&doi=10.1021%2facsaem.5c00803&partnerID=40&md5=65629196be936b3aa9b4d5d072de0f1creponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)#PLACEHOLDER_PARENT_METADATA_VALUE#info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2021-2023/PID2021-123308OB-I00ACS Applied Energy Materialshttps://doi.org/10.1021/acsaem.5c00803Síinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/4064472026-05-22T06:33:51Z |
| score |
15.81155 |