Tuning Electrocatalytic\nOxygen Reduction Reaction\nwith Dynamic Control of Electrochemical Interfaces

Abstract

Herein, we report the tuning of the activity and selectivity\nof\nthe oxygen reduction reaction (ORR) through the dynamic regulation\nof the electrochemical interfaces to surpass the performance of conventional\nelectrocatalysis. This is achieved by applying an oscillating potential\nbetween the ORR operating potential and anion adsorbing potential\non a gold electrode. Oscillating potential enhances the selectivity\nfor H₂O₂ by up to 1.35 times compared to the\nstatic potential, as confirmed by rotating ring-disk electrode and\nfluorescence assay measurements. We showed that the enhanced selectivity\ndepends on dynamic adsorption and desorption of anions, and the enhancement\noccurs in the millisecond time scale or shorter. The transient selectivity\nto H₂O₂ can reach ∼97% within the first\n5 ms after potential switching. Our results suggest that the dynamic\ninterface can create a transient but unique microenvironment for new\nreactivity that cannot be reproduced under static conditions, which\noffers a new dimension in controlling electrocatalysis.