Formation and Migration of Oxygen Vacancies in SrCoO3 and their effect on Oxygen Evolution Reactions

Handle URI:
http://hdl.handle.net/10754/617509
Title:
Formation and Migration of Oxygen Vacancies in SrCoO3 and their effect on Oxygen Evolution Reactions
Authors:
Tahini, Hassan A.; Tan, Xin; Schwingenschlögl, Udo ( 0000-0003-4179-7231 ) ; Smith, Sean C.
Abstract:
Perovskite SrCoO3 is a potentially useful material for promoting the electrocatalytic oxygen evolution reaction, with high activities predicted theoretically and observed experimentally for closely related doped perovskite materials. However, complete stoichiometric oxidation is very difficult to realize experimentally – in almost all cases there are significant fractions of oxygen vacancies present. Here, using first principles calculations we study oxygen vacancies in perovskite SrCoO3 from thermodynamic, electronic and kinetic points of view. We find that an oxygen vacancy donates two electrons to neighboring Co sites in the form of localized charge. The formation energy of a single vacancy is very low and estimated to be 1.26 eV in the dilute limit. We find that a vacancy is quite mobile with a migration energy of ~0.5 eV. Moreover, we predict that oxygen vacancies exhibit a tendency towards clustering which is in accordance with the material’s ability to form a variety of oxygen-deficient structures. These vacancies have a profound effect on the material’s ability to facilitate OER, increasing the overpotential from ~0.3 V for the perfect material to ~0.7 for defective surfaces. A moderate compressive biaxial strain (2%) is predicted here to increase the surface oxygen vacancy formation energy by ca. 30%, thus reducing the concentration of surface vacancies and thereby preserving the OER activity of the material.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Formation and Migration of Oxygen Vacancies in SrCoO 3 and their effect on Oxygen Evolution Reactions 2016 ACS Catalysis
Publisher:
American Chemical Society (ACS)
Journal:
ACS Catalysis
Issue Date:
18-Jul-2016
DOI:
10.1021/acscatal.6b00937
Type:
Article
ISSN:
2155-5435; 2155-5435
Sponsors:
This research was undertaken with the assistance of UNSW Australia SPF01 funding (SCS). We acknowledge generous allocations of supercomputing time at the Pawsey Supercomputing Centre via the Australian National Computational Merit Allocation Scheme (NCMAS project fr2) and the Energy and Resources Merit Allocation Scheme of the Pawsey Supercomputing Centre (project pawsey0111). Additional computational resources were provided by KAUST on the Shaheen II supercomputer.
Additional Links:
http://pubs.acs.org/doi/abs/10.1021/acscatal.6b00937
Appears in Collections:
Articles

Full metadata record

DC FieldValue Language
dc.contributor.authorTahini, Hassan A.en
dc.contributor.authorTan, Xinen
dc.contributor.authorSchwingenschlögl, Udoen
dc.contributor.authorSmith, Sean C.en
dc.date.accessioned2016-07-26T09:19:10Z-
dc.date.available2016-07-26T09:19:10Z-
dc.date.issued2016-07-18-
dc.identifier.citationFormation and Migration of Oxygen Vacancies in SrCoO 3 and their effect on Oxygen Evolution Reactions 2016 ACS Catalysisen
dc.identifier.issn2155-5435-
dc.identifier.issn2155-5435-
dc.identifier.doi10.1021/acscatal.6b00937-
dc.identifier.urihttp://hdl.handle.net/10754/617509-
dc.description.abstractPerovskite SrCoO3 is a potentially useful material for promoting the electrocatalytic oxygen evolution reaction, with high activities predicted theoretically and observed experimentally for closely related doped perovskite materials. However, complete stoichiometric oxidation is very difficult to realize experimentally – in almost all cases there are significant fractions of oxygen vacancies present. Here, using first principles calculations we study oxygen vacancies in perovskite SrCoO3 from thermodynamic, electronic and kinetic points of view. We find that an oxygen vacancy donates two electrons to neighboring Co sites in the form of localized charge. The formation energy of a single vacancy is very low and estimated to be 1.26 eV in the dilute limit. We find that a vacancy is quite mobile with a migration energy of ~0.5 eV. Moreover, we predict that oxygen vacancies exhibit a tendency towards clustering which is in accordance with the material’s ability to form a variety of oxygen-deficient structures. These vacancies have a profound effect on the material’s ability to facilitate OER, increasing the overpotential from ~0.3 V for the perfect material to ~0.7 for defective surfaces. A moderate compressive biaxial strain (2%) is predicted here to increase the surface oxygen vacancy formation energy by ca. 30%, thus reducing the concentration of surface vacancies and thereby preserving the OER activity of the material.en
dc.description.sponsorshipThis research was undertaken with the assistance of UNSW Australia SPF01 funding (SCS). We acknowledge generous allocations of supercomputing time at the Pawsey Supercomputing Centre via the Australian National Computational Merit Allocation Scheme (NCMAS project fr2) and the Energy and Resources Merit Allocation Scheme of the Pawsey Supercomputing Centre (project pawsey0111). Additional computational resources were provided by KAUST on the Shaheen II supercomputer.en
dc.language.isoenen
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttp://pubs.acs.org/doi/abs/10.1021/acscatal.6b00937en
dc.rightsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Catalysis, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acscatal.6b00937.en
dc.titleFormation and Migration of Oxygen Vacancies in SrCoO3 and their effect on Oxygen Evolution Reactionsen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalACS Catalysisen
dc.eprint.versionPost-printen
dc.contributor.institutionIntegrated Materials Design Centre (IMDC), School of Chemical Engineering, UNSW Australia, Sydney, NSW 2052, Australiaen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorSchwingenschlögl, Udoen
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