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dc.contributor.authorShinagawa, Tatsuya
dc.contributor.authorTakanabe, Kazuhiro
dc.date.accessioned2015-05-03T14:16:03Z
dc.date.available2015-05-03T14:16:03Z
dc.date.issued2015-04-24
dc.identifier.citationImpact of solute concentration on the electrocatalytic conversion of dissolved gases in buffered solutions 2015, 287:465 Journal of Power Sources
dc.identifier.issn03787753
dc.identifier.doi10.1016/j.jpowsour.2015.04.091
dc.identifier.urihttp://hdl.handle.net/10754/552132
dc.description.abstractTo maintain local pH levels near the electrode during electrochemical reactions, the use of buffer solutions is effective. Nevertheless, the critical effects of the buffer concentration on electrocatalytic performances have not been discussed in detail. In this study, two fundamental electrochemical reactions, oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR), on a platinum rotating disk electrode are chosen as model gas-related aqueous electrochemical reactions at various phosphate concentrations. Our detailed investigations revealed that the kinetic and limiting diffusion current densities for both the ORR and HOR logarithmically decrease with increasing solute concentration (log|jORR|=-0.39c+0.92,log|jHOR|=-0.35c+0.73). To clarify the physical aspects of this phenomenon, the electrolyte characteristics are addressed: with increasing phosphate concentration, the gas solubility decrease, the kinematic viscosity of the solution increase and the diffusion coefficient of the dissolved gases decrease. The simulated limiting diffusion currents using the aforementioned parameters match the measured ones very well (log|jORR|=-0.43c+0.99,log|jHOR|=-0.40c+0.54), accurately describing the consequences of the electrolyte concentration. These alterations of the electrolyte properties associated with the solute concentration are universally applicable to other aqueous gas-related electrochemical reactions because the currents are purely determined by mass transfer of the dissolved gases. © 2015 The Authors.
dc.publisherElsevier BV
dc.relation.urlhttp://linkinghub.elsevier.com/retrieve/pii/S037877531500748X
dc.rightsThis is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ).
dc.subjectFuel cells
dc.subjectOxygen reduction reaction
dc.subjectHydrogen oxidation reaction
dc.subjectConductivity
dc.subjectSolution resistance
dc.titleImpact of solute concentration on the electrocatalytic conversion of dissolved gases in buffered solutions
dc.typeArticle
dc.contributor.departmentCatalysis for Energy Conversion (CatEC)
dc.contributor.departmentChemical Science Program
dc.contributor.departmentKAUST Catalysis Center (KCC)
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.identifier.journalJournal of Power Sources
dc.eprint.versionPublisher's Version/PDF
kaust.personTakanabe, Kazuhiro
kaust.personShinagawa, Tatsuya
refterms.dateFOA2018-06-14T05:01:27Z
dc.date.published-online2015-04-24
dc.date.published-print2015-08


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