Papers

Peer-reviewed
Dec, 2005

Potential oscillations in galvanostatic electrooxidation of formic acid on platinum: A time-resolved surface-enhanced infrared study

JOURNAL OF PHYSICAL CHEMISTRY B
  • G Samjeske
  • ,
  • A Miki
  • ,
  • S Ye
  • ,
  • A Yamakata
  • ,
  • Y Mukouyama
  • ,
  • H Okamoto
  • ,
  • M Osawa

Volume
109
Number
49
First page
23509
Last page
23516
Language
English
Publishing type
Research paper (scientific journal)
DOI
10.1021/jp055220j
Publisher
AMER CHEMICAL SOC

The mechanism of temporal potential oscillations that occur during galvanostatic formic acid oxidation on a Pt electrode has been investigated by time-resolved surface-enhanced infrared absorption spectroscopy (SEIRAS). Carbon monoxide (CO) and formate were found to adsorb on the surface and change their coverages synchronously with the temporal potential oscillations. Isotopic solution exchange (from (HCOOH)-C-13 to (HCOOH)-C-12) and potential step experiments revealed that the oxidation of formic acid proceeds dominantly through adsorbed formate and the decomposition of formate to CO2 is the rate-determining step of the reaction. Adsorbed CO blocks the adsorption of formate and also suppresses the decomposition of formate to CO2, which raises the potential to maintain the applied current. The oxidative removal of CO at a high limiting potential increases the coverage of formate and accelerates the decomposition of formate, resulting in a potential drop and leading to the formation of CO. This cycle repeats itself to give the sustained temporal potential oscillations. The oscillatory dynamics can be explained by using a nonlinear rate equation originally proposed to explain the decomposition of formate and acetate on transition metal surfaces in UHV.

Link information
DOI
https://doi.org/10.1021/jp055220j
J-GLOBAL
https://jglobal.jst.go.jp/en/detail?JGLOBAL_ID=200902285235953656
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000233864300059&DestApp=WOS_CPL
URL
http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=200902285235953656
ID information
  • DOI : 10.1021/jp055220j
  • ISSN : 1520-6106
  • J-Global ID : 200902285235953656
  • Web of Science ID : WOS:000233864300059

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