Packed powder electrodes for characterizing the reactivity of granular iron in borate solutions

James T. Nurmi, Joel Z. Bandstra, Paul Tratnyek

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Electrochemical aspects of the corrosion of iron metal have been studied using polished disk, wire, and iron coupon electrodes, but these model systems do not represent many characteristics of the granular iron used in environmental remediation applications. To address this issue, we have modified a rotating disk electrode with a cavity that accommodates a wide range of iron powders. By comparison with conventional Fe0 and Pt0 disk electrodes, we found that our powder disk electrodes (PDEs) packed with unpretreated, <147 μm granular iron give anodic polarization curves that are unaffected by the underlying disk material and are consistent with a large electroactive surface area of iron that is initially coated with an air-formed passive film. Thus, we believe this electrode design will allow us to begin electrochemical studies of the reduction of aqueous environmental contaminants by relevant iron powders. In preparation for this, we report here on some of the experimental factors that effect response of an iron PDE in pH 8.4 borate buffer. Cavity size and rotation rate have synergistic effects that suggest that most of the iron powder is electroactive, hydrogen evolution in the active region is kinetically limited, and iron dissolution in the active region is affected by mass transport of solutes out of the cavity pore space and by the formation of a passivating film.

Original languageEnglish (US)
JournalJournal of the Electrochemical Society
Volume151
Issue number6
DOIs
StatePublished - 2004

Fingerprint

Borates
borates
Powders
Iron powder
Iron
reactivity
iron
Electrodes
electrodes
Anodic polarization
cavities
Rotating disks
Hydrogen
Buffers
Dissolution
Mass transfer
Metals
Wire
Impurities
Corrosion

ASJC Scopus subject areas

  • Electrochemistry
  • Surfaces, Coatings and Films
  • Surfaces and Interfaces

Cite this

Packed powder electrodes for characterizing the reactivity of granular iron in borate solutions. / Nurmi, James T.; Bandstra, Joel Z.; Tratnyek, Paul.

In: Journal of the Electrochemical Society, Vol. 151, No. 6, 2004.

Research output: Contribution to journalArticle

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