ISSN:
1040-0397
Keywords:
Chemically modified electrode
;
σ-bonded pyrrole iron porphrin
;
Catalytic hydrogen peroxide reduction
;
Linear rotation-scan method
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Reduction of hydrogen peroxide at a glassy carbon (GC) electrode modified with σ-bonded pyrrole iron(III) octaethylporphyrin complex, (OEP)Fe(Pyr), was studied by cyclic voltammetry and a rotating disk electrode. In 0.1 N NaOH solution, it is shown that such an (OEP)Fe(Pyr)/GC electrode has a significant catalytic activity towards hydrogen peroxide reduction (ED = -0.80 V, k = 0.066 cm s-1); however, the electrode stability is low. The deactivation is observed when the reaction charge (Q) is passing through the (OEP)Fe(Pyr)/GC disk electrode. A linear rotation scan method is applied to study the kinetic process by determining the disk electrochemical response (iD) to rotation rate (ω) at a definite disk potential (ED). Considering that the number of adsorbed electroreduced catalyst molecules (Red) varies according to the disk potential, a factor θ (= ΓRed/(ΓRed + ΓOx)) is introduced to describe the electrode surface area fraction for electroreduced species. The obtained Koutecky-Levich equation is applicable whatever the potential is.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elan.1140070606
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