Electrochemical Promotion of C2H4 Oxidation on Pt Using a Bipolar Design

1 Electrochemical Promotion of C2H4 Oxidation on Pt Using a Bipolar Design 

As shown in Fig. 12.7 application of a potential between the two terminal Au electrodes induces NEMCA on the Pt film which is not connected to any metal wire but is simply in contact with the YSZ solid electrolyte. 

The observed rate enhancement is roughly half of that obtained in the same setup when the Pt catalyst is connected to a wire and potential is applied between it and one of the Au terminal electrodes.8 

As in aqueous electrochemistry it appears that application of a potential between the two terminal (Au) electrodes leads to charge separation on the Pt film so that half of it is charged positively and half negatively8 thus establishing two individual galvanic cells. The Pt film becomes a bipolar electrode and half of it is polarized anodically while the other half is polarized cathodically. The fact that p is smaller (roughly half) than that obtained upon anodic polarization in a classical electrochemical promotion experiment can be then easily explained. 

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