Understanding the Reaction Energetics of Oxygen-evolving Electrocatalysts

Abstract

Electrocatalysts are crucial for efficient electrochemical devices that enable sustainable chemical transformations. Electrocatalyst activity has been correlated to the thermodynamics of reaction intermediates that balance intermediate formation and desorption. However, a lack of detailed experimental thermodynamic information about reaction energetics limits the design of next-generation electrocatalysts. Here we show kinetic and electroadsorption studies of precisely terminated first-row transition metal ruthenium oxide nanocrystals that elucidate how material chemistry influences the oxygen evolution reaction activity and reaction energetics. We established the energy scaling relations between the *OH, *O, and *OOH intermediates involved in the oxygen evolution reaction. These energy scaling relations were leveraged to design an FeMnRuO_x electrocatalyst with an 876% increase in mass activity compared to RuO₂. Our study highlights the potential for precise nanocrystal synthesis and electroadsorption analysis to rationally guide the design of next-generation electrocatalysts with improved activity and further elucidate mechanisms of catalyst activation.