Probing intermediate configurations of oxygen evolution catalysis across the light spectrum

Abstract

The oxygen evolution reaction is crucial to sustainable electro- and photo-electrochemical approaches to chemical energy production (for example, H2). Although mechanistic descriptions of the oxygen evolution reaction have been proposed, the frontier challenge is to extract the molecular details of its elementary steps. Here we discuss how advances in spectroscopy and theory are allowing for configurations of reaction intermediates to be elucidated, distinguishing between experimental approaches (static and dynamic) across a range of surface oxygen binding energies on catalysts (from ruthenium to titanium oxides). We outline how interpreting X-ray and optical spectra relies on established and newly implemented computational techniques. A key emphasis is on detecting adsorbed oxygen intermediates at the oxide/water interface by their chemical composition, electronic and vibrational levels and ion–electron kinetic pathways. Integrating the computational advances with the experimental spectra along these lines could ultimately resolve the elementary steps, elucidating how each intermediate leads to another during oxygen evolution reaction. Oxygen evolution is a critical reaction in the context of renewable fuel production via (photo)electrochemical approaches, yet our understanding of the molecular details of the reaction is limited. Here, the authors explore how specific spectroscopic probes and theory can be combined to reveal the elementary reaction steps.