The kinetics of the oxygen reduction reaction on steel in alkaline solution

Dominic F Gervasio, Joe H. Payer

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

Oxygen electroreduction on steel is considered the major electrochemical process on steel under cathodic protection (CP) in air. The kinetics of O 2 reduction on steel in aqueous alkaline (pH = 14) electrolyte was examined to probe the electrochemistry of steel during CP. The cyclic potential ring measurement (CPRM) rotating ring disk electrode (RRDE) method was used to study the O 2 reduction on steel, because the CPRM RRDE method permitted quantitative detection of the peroxide formed during O 2 electroreduction. Two regimes of O 2 reduction on steel were observed. The first regime, between -0.2 to -0.9 V versus SCE (saturated calomel electrode), was accompanied by virtually 100% electrochemical conversion of O 2 to peroxide. The second regime, between -0.9 to -1.3 volt versus SCE, corresponded mainly to hydroxide formation. O 2 reduction and peroxide oxidation currents were well behaved - that is, increased linearly with the inverse square root of all rotations rates (400 to 3600 rpm) - so a mechanistic analysis of the ring and disk data could be done to determine the potential dependent rate constants for O 2 reduction on steel. A series mechanism was found operative. Oxygen electroreduction was found to proceed by two sequential 2e - steps, first yielding peroxide and then hydroxide. This study shows peroxide generation is expected on steel in air at potentials as highly negative as -1 V versus SCE at pH = 14, so coating disbonding models should consider the effects of peroxide on coated pipelines under cathodic polarization.

Original languageEnglish (US)
Title of host publicationProceedings - Electrochemical Society
EditorsJ. Prakash, D. Chu, D. Scherson, M. Enayetullah, T. Bae
Pages58-70
Number of pages13
VolumePV 2003-30
Publication statusPublished - 2005
Externally publishedYes
EventFundamental Understanding of Electrode Processes, in Memory of Professor Ernest B. Yeager - Proceedings of the International Symposium - Orlando, FL, United States
Duration: Oct 12 2003Dec 17 2003

Other

OtherFundamental Understanding of Electrode Processes, in Memory of Professor Ernest B. Yeager - Proceedings of the International Symposium
CountryUnited States
CityOrlando, FL
Period10/12/0312/17/03

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ASJC Scopus subject areas

  • Engineering(all)

Cite this

Gervasio, D. F., & Payer, J. H. (2005). The kinetics of the oxygen reduction reaction on steel in alkaline solution. In J. Prakash, D. Chu, D. Scherson, M. Enayetullah, & T. Bae (Eds.), Proceedings - Electrochemical Society (Vol. PV 2003-30, pp. 58-70). [4]