Molecular Electrocatalysis for Oxygen Reduction by Cobalt Porphyrins Adsorbed at Liquid/Liquid Interfaces

• Published in: J. Am. Chem. Soc. (ISSN: 0002-7863), vol. 132, p. 2655-2662
• American Chemical Society, 2010

Molecular electrocatalysis for oxygen reduction at a polarized water/1,2-dichloroethane (DCE) interface was studied, involving aqueous protons, ferrocene (Fc) in DCE and amphiphilic cobalt porphyrin catalysts adsorbed at the interface. The catalyst, (2,8,13,17-tetraethyl-3,7,12,18-tetramethyl-5-paminophenylporphyrin) cobalt(II) (CoAP), functions like conventional cobalt porphyrins, activating O2 via coordination by the formation of a superoxide structure. Furthermore, due to the hydrophilic nature of the aminophenyl group, CoAP has a strong affinity for the water/DCE interface as evidenced by lipophilicity mapping calculations and surface tension measurements, facilitating the protonation of the CoAP-O2 complex and its reduction by ferrocene. The reaction is electrocatalytic as its rate depends on the applied Galvani potential difference between the two phases.

Keywords: Oxygen reduction ; Proton reduction ; Decamethylferrocene ; Liquid/liquid interface ; Voltammetry ; Immiscible Electrolyte-Solutions ; Scanning Electrochemical Microscopy ; Liquid-Liquid Interface ; Ferrocene Derivatives ; Molecular-Oxygen ; Polarized Interface ; Perchloric-Acid ; Proton-Transfer ; Mechanism ; Dioxygen

Reference

• EPFL-ARTICLE-148794
• doi:10.1016/j.jelechem.2009.11.029
• View record in Web of Science

Record created on 2010-05-17, modified on 2012-03-21