In this work a new composite electrode for the electrocatalytic reduction of oxygen (ORR) is presented. For this purpose, glassy carbon electrodes (GC) were modified with CoII and FeIII octaethylporphyrins. The system that presents the highest electrocatalytic activity towards ORR is GC modified with a mixture of both octaethylporphyrins in 1:1 volume proportion (GC Co-Fe 1:1) over the GC electrodes modified with CoII and FeIII octaethylporphyrins separately. This modified electrode can reduce O2 through two reduction processes (four electrons each), by the generation of H2O as final product, in two active sites of different chemical nature. All the electrodic systems were morphologically characterized by atomic-force microscopy (AFM) and electrically characterized by electrochemical impedance spectroscopy (EIS). It was found that the electroactive system (GC Co-Fe 1:1) presents high differences on its surface and performs the lowest charge transfer resistance (Rct) in comparison to the rest of the modified systems and GC itself.
|Number of pages||17|
|Journal||International Journal of Electrochemical Science|
|Publication status||Published - 2018|
Bibliographical noteFunding Information:
ACKNOWLEDGEMENTS The authors would like to acknowledge the financial support provided by FONDECYT Project No.: 1170340 and No.: 1160324. M.J.A. acknowledges Dicyt-Usach financial support.
© 2018 The Authors.
- Dioxygen reduction
- Modified electrode
- Porphyrin complex mixtures
- Synergic effect