Accession Number:

ADA200024

Title:

Oxygen Reduction on Adsorbed Iron Tetrapyridino Porphyrazine

Descriptive Note:

Technical rept. 1987-1988

Corporate Author:

CASE WESTERN RESERVE UNIV CLEVELAND OH

Report Date:

1988-09-01

Pagination or Media Count:

46.0

Abstract:

The electrocatalytic properties of iron tetrapyridino porphyrazine FeTPyPz for the reduction of O2 in alkaline media have been examined with cyclic voltammetry and rotating ring disk techniques. Four distinct redox peaks are observed in the absence of O2 in solution for this material adsorbed at monolayer coverages on ordinary pyrolytic graphite surfaces. The onset for O2 reduction appears to coincide with the voltammetric peak associated with the metal centered FeII TPyPzFeIIITPyPz transition. No hydrogen peroxide is detected at the ring in this potential range indicating that the reaction takes place by a four electron pathway. This is in contrast with the behavior observed. This change in the mechanism has been attributed to the further reduction of the ion center in the macrocycle rendering an FeITPyPz species. If the electrode is polarized at potentials more negative than -0.8 V vs SCE, however, the reduction proceeds once again without generation of H2O2 in the solution phase. Keywords Oxygen reduction, Electrocatalysts, Transition metal macrocycles, Tetrapyridino porphyrazine.

Subject Categories:

  • Organic Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE