Oxide Deconstruction in Mixed-Metal Oxygen Electrocatalysts

Mixed-metal oxides are often utilized for oxygen electrocatalysis due to their superior activity. In this work, we focus on an emerging class of mixed-metal oxygen evolution catalysts and study their activity and structural evolution with particular focus on their performance in harsh, acidic conditions. While modified catalysts often exhibit superior activity, we show that this activity enhancement can simply be due to in-situ catalyst deconstruction to form an amorphous overlayer with increased active-site density. Large-atom modifiers promote the formation of active sites through dimensional reduction resulting in an increase in terminal, catalytically active edge sites. Here, we utilize a combination of advanced techniques including operando extended X-ray absorption fine-structure (EXAFS), operando Raman, and ambient-pressure X-ray photoelectron spectroscopy to gain new insights regarding catalyst evolution during the oxygen evolution reaction.