Electrocatalytic aspects of iron phthalocyanine and its μ-oxo derivatives dispersed on high surface area carbon

A. A. Tanaka, C. Fierro, Daniel Alberto Scherson, E. B. Yeager

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Abstract

The cyclic voltammetry of iron phthalocyanine (FePc) and its two μ-oxo derivatives obtained by mixing the materials in dry form with high-area Vulcan XC-72 carbon yielded a common set of voltammetric peaks. This provides evidence for the presence of a single type of surface species for the macrocycle in its various forms. The electrochemical activity of these dispersed specimens for O2 reduction in alkaline media using thin porous coating-rotating disk techniques was found to be essentially the same for both μ-oxo derivatives. Comparable activities were observed in the case of bulk monomeric FePc only after polarizing the electrodes at fairly negative potentials. Some differences in activity were observed, however, for the materials in gas-fed electrodes of the type used in fuel cells in 4 M NaOH at 60°C. Based on the results obtained in this work and quantum mechanical considerations, it has been concluded that (i) the increase in conductivity induced by the exposure of FePc to dioxygen is most likely due to the formation of μ-oxo-type derivatives, and (ii) it is not necessary to invoke a metal spin crossover mechanism as the key factor in explaining the high electrocatalytic activity of FePc for the reduction of O2, as has been proposed earlier in the literature.

Original languageEnglish
Pages (from-to)3799-3807
Number of pages9
JournalJournal of physical chemistry
Volume91
Issue number14
Publication statusPublished - 1987 Dec 1
Externally publishedYes

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Carbon
Iron
Derivatives
iron
carbon
Electrodes
Rotating disks
Cyclic voltammetry
electrodes
Fuel cells
rotating disks
Gases
Metals
Oxygen
fuel cells
Coatings
crossovers
coatings
conductivity
iron phthalocyanine

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Electrocatalytic aspects of iron phthalocyanine and its μ-oxo derivatives dispersed on high surface area carbon. / Tanaka, A. A.; Fierro, C.; Scherson, Daniel Alberto; Yeager, E. B.

In: Journal of physical chemistry, Vol. 91, No. 14, 01.12.1987, p. 3799-3807.

Research output: Contribution to journalArticle

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