Insight on Tafel slopes from a microkinetic analysis of aqueous electrocatalysis for energy conversion

Handle URI:
http://hdl.handle.net/10754/578916
Title:
Insight on Tafel slopes from a microkinetic analysis of aqueous electrocatalysis for energy conversion
Authors:
Shinagawa, Tatsuya ( 0000-0002-5240-7342 ) ; Garcia Esparza, Angel T. ( 0000-0002-4884-171X ) ; Takanabe, Kazuhiro ( 0000-0001-5374-9451 )
Abstract:
Microkinetic analyses of aqueous electrochemistry involving gaseous H2 or O2, i.e., hydrogen evolution reaction (HER), hydrogen oxidation reaction (HOR), oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), are revisited. The Tafel slopes used to evaluate the rate determining steps generally assume extreme coverage of the adsorbed species (θ ≈ 0 or ≈1), although, in practice, the slopes are coverage-dependent. We conducted detailed kinetic analyses describing the coverage-dependent Tafel slopes for the aforementioned reactions. Our careful analyses provide a general benchmark for experimentally observed Tafel slopes that can be assigned to specific rate determining steps. The Tafel analysis is a powerful tool for discussing the rate determining steps involved in electrocatalysis, but our study also demonstrated that overly simplified assumptions led to an inaccurate description of the surface electrocatalysis. Additionally, in many studies, Tafel analyses have been performed in conjunction with the Butler-Volmer equation, where its applicability regarding only electron transfer kinetics is often overlooked. Based on the derived kinetic description of the HER/HOR as an example, the limitation of Butler-Volmer expression in electrocatalysis is also discussed in this report.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; KAUST Catalysis Center (KCC)
Citation:
Insight on Tafel slopes from a microkinetic analysis of aqueous electrocatalysis for energy conversion 2015, 5:13801 Scientific Reports
Publisher:
Nature Publishing Group
Journal:
Scientific Reports
Issue Date:
8-Sep-2015
DOI:
10.1038/srep13801
Type:
Article
ISSN:
2045-2322
Additional Links:
http://www.nature.com/doifinder/10.1038/srep13801
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; KAUST Catalysis Center (KCC)

Full metadata record

DC FieldValue Language
dc.contributor.authorShinagawa, Tatsuyaen
dc.contributor.authorGarcia Esparza, Angel T.en
dc.contributor.authorTakanabe, Kazuhiroen
dc.date.accessioned2015-09-30T08:56:38Zen
dc.date.available2015-09-30T08:56:38Zen
dc.date.issued2015-09-08en
dc.identifier.citationInsight on Tafel slopes from a microkinetic analysis of aqueous electrocatalysis for energy conversion 2015, 5:13801 Scientific Reportsen
dc.identifier.issn2045-2322en
dc.identifier.doi10.1038/srep13801en
dc.identifier.urihttp://hdl.handle.net/10754/578916en
dc.description.abstractMicrokinetic analyses of aqueous electrochemistry involving gaseous H2 or O2, i.e., hydrogen evolution reaction (HER), hydrogen oxidation reaction (HOR), oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), are revisited. The Tafel slopes used to evaluate the rate determining steps generally assume extreme coverage of the adsorbed species (θ ≈ 0 or ≈1), although, in practice, the slopes are coverage-dependent. We conducted detailed kinetic analyses describing the coverage-dependent Tafel slopes for the aforementioned reactions. Our careful analyses provide a general benchmark for experimentally observed Tafel slopes that can be assigned to specific rate determining steps. The Tafel analysis is a powerful tool for discussing the rate determining steps involved in electrocatalysis, but our study also demonstrated that overly simplified assumptions led to an inaccurate description of the surface electrocatalysis. Additionally, in many studies, Tafel analyses have been performed in conjunction with the Butler-Volmer equation, where its applicability regarding only electron transfer kinetics is often overlooked. Based on the derived kinetic description of the HER/HOR as an example, the limitation of Butler-Volmer expression in electrocatalysis is also discussed in this report.en
dc.language.isoenen
dc.publisherNature Publishing Groupen
dc.relation.urlhttp://www.nature.com/doifinder/10.1038/srep13801en
dc.rightsThis work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/en
dc.titleInsight on Tafel slopes from a microkinetic analysis of aqueous electrocatalysis for energy conversionen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.identifier.journalScientific Reportsen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorTakanabe, Kazuhiroen
kaust.authorShinagawa, Tatsuyaen
kaust.authorGarcia Esparza, Angel T.en
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