Ding-Yuan Kuo1 Hanjong Paik1 Darrell Schlom1 Jin Suntivich1

1, Cornell University, Ithaca, New York, United States

A catalyst operates by stabilizing reaction intermediates through surface adsorption. In the oxygen evolution reaction (OER), an electrochemical reaction that limits the water splitting’s efficiency, the OER catalyst stabilizes the intermediates by electrochemically stabilizing oxygen-containing intermediates during the proton and electron transfer events. This presentation will discuss our measurements of the proton and electron transfer rates during the intermediate stabilizations, specifically the de-protonation of OH* to O*. While these measurements are common for homogeneous catalysts, similar experiments have not been reported on heterogeneous surfaces, in particular oxides. Our experiment uses rate-dependent cyclic voltammetry (CV) to probe these rate constants on single-orientation RuO2(110). By examining a series of electrolytes, we further identify how the rate constant varies with pH to determine whether the proton and electron transfers are coupled or decoupled. Our results offer insights into the surface electron transfer kinetics on heterogeneous surfaces and provide directions to the future design of superior OER catalysts.