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New Insights into the Oxygen Reduction Reaction Mechanism on Pt (111): A Detailed Electrochemical Study
Author(s) -
GómezMarín Ana M.,
Feliu Juan M.
Publication year - 2013
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201200847
Subject(s) - electrochemistry , oxygen reduction reaction , mechanism (biology) , oxygen reduction , reaction mechanism , chemistry , reduction (mathematics) , oxygen , catalysis , electrode , organic chemistry , physics , geometry , mathematics , quantum mechanics
The oxygen reduction reaction (ORR) is undoubtedly the most important fuel‐cell cathodic reaction. In this work, a detailed electrochemical analysis of the ORR on Pt (111) in nonadsorbing electrolytes was performed, which included the high‐potential region E up =1.15 V while ensuring the electrode surface structure stability. Our results suggest that the reduction of a soluble intermediate species formed during the ORR is the rate‐determining step in the whole reaction mechanism. This species does not undergo any other electrochemical reaction at E >0.9 V and may accumulate close to the electrode surface. Together with dissolved O 2 , this intermediate may modify the oxide‐growth dynamics on Pt (111). Hence, both species interact with the electrode surface through complex catalytic networks. Under certain experimental conditions, oxygenated species from the oxidation of Pt (111) may enhance the overall ORR current. These results propose an alternative to explain the current state of the art for this fundamental process.