Mechanistic Switching by Hydronium Ion Activity for Hydrogen Evolution and Oxidation over Polycrystalline Platinum Disk and Platinum/Carbon Electrodes

Handle URI:
http://hdl.handle.net/10754/575604
Title:
Mechanistic Switching by Hydronium Ion Activity for Hydrogen Evolution and Oxidation over Polycrystalline Platinum Disk and Platinum/Carbon Electrodes
Authors:
Shinagawa, Tatsuya ( 0000-0002-5240-7342 ) ; Garcia Esparza, Angel T. ( 0000-0002-4884-171X ) ; Takanabe, Kazuhiro ( 0000-0001-5374-9451 )
Abstract:
Fundamental electrochemical reactions, namely the hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR), are re-evaluated under various pH conditions over polycrystalline Pt disk electrodes and Pt/C electrodes to investigate the overpotential and Tafel relations. Kinetic trends are observed and can be classified into three pH regions: acidic (1-5), neutral (5-9), and alkaline (9-13). Under neutral conditions, in which H2O becomes the primary reactant, substantial overpotential, which is not affected by pH and the supporting electrolyte type, is required for electrocatalysis in both directions. This ion independence, including pH, suggests that HER/HOR performance under neutral conditions solely reflects the intrinsic electrocatalytic activity of Pt in the rate determining steps, which involve electron transfer with water molecules. A global picture of the HER/HOR, resulting from mechanistic switching accompanied by change in pH, is detailed.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Chemical Science Program; KAUST Catalysis Center (KCC); Chemical Science Program; Catalysis for Energy Conversion (CatEC)
Publisher:
Wiley-Blackwell
Journal:
ChemElectroChem
Issue Date:
22-Jul-2014
DOI:
10.1002/celc.201402085
Type:
Article
ISSN:
2196-0216
Sponsors:
The research reported in this work was supported by the King Abdullah University of Science and Technology.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; 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.accessioned2015-08-24T08:34:00Zen
dc.date.available2015-08-24T08:34:00Zen
dc.date.issued2014-07-22en
dc.identifier.issn2196-0216en
dc.identifier.doi10.1002/celc.201402085en
dc.identifier.urihttp://hdl.handle.net/10754/575604en
dc.description.abstractFundamental electrochemical reactions, namely the hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR), are re-evaluated under various pH conditions over polycrystalline Pt disk electrodes and Pt/C electrodes to investigate the overpotential and Tafel relations. Kinetic trends are observed and can be classified into three pH regions: acidic (1-5), neutral (5-9), and alkaline (9-13). Under neutral conditions, in which H2O becomes the primary reactant, substantial overpotential, which is not affected by pH and the supporting electrolyte type, is required for electrocatalysis in both directions. This ion independence, including pH, suggests that HER/HOR performance under neutral conditions solely reflects the intrinsic electrocatalytic activity of Pt in the rate determining steps, which involve electron transfer with water molecules. A global picture of the HER/HOR, resulting from mechanistic switching accompanied by change in pH, is detailed.en
dc.description.sponsorshipThe research reported in this work was supported by the King Abdullah University of Science and Technology.en
dc.publisherWiley-Blackwellen
dc.titleMechanistic Switching by Hydronium Ion Activity for Hydrogen Evolution and Oxidation over Polycrystalline Platinum Disk and Platinum/Carbon Electrodesen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical Science Programen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.contributor.departmentChemical Science Programen
dc.contributor.departmentCatalysis for Energy Conversion (CatEC)en
dc.identifier.journalChemElectroChemen
kaust.authorTakanabe, Kazuhiroen
kaust.authorShinagawa, Tatsuyaen
kaust.authorGarcia Esparza, Angel T.en
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.