Bipolar electrodes for rapid screening of electrocatalysts.

We report a method for rapid screening of arrays of electrocatalyst candidates. The approach is based on simultaneous activation of the oxygen reduction reaction (ORR) and Ag electrodissolution at the cathodic and anodic poles, respectively, of bipolar electrodes (BPEs). Because the electrochemical activity of the two poles is directly coupled via the BPE, the extent of Ag electrodissolution is directly related to the ORR activity. The screening process lasts ~12 min. Because Ag dissolution provides a permanent record of catalyst activity, the screening results can be determined by simple optical microscopy after the electrochemical experiment. The method has the potential to provide quantitative information about electrocatalyst activity.