A Dissolution/Precipitation Equilibrium on the Surface of Iridium‐Based Perovskites Controls Their Activity as Oxygen Evolution Reaction Catalysts in Acidic Media
Year: 2019
Type: article
Abstract: Recently, IrV‐based perovskite‐like materials were proposed as oxygen evolution reaction (OER) catalysts in acidic media with promising performance. However, iridium dissolution and surface reconstruction were observed, questioning the real active sites on the surface of these catalysts. In this work, Sr2MIr(V)O6(M=Fe, Co) and Sr2Fe0.5Ir0.5(V)O4were explored as OER catalysts in acidic media. Their activities were observed to be roughly equal to those previously reported for La2LiIrO6or Ba2PrIrO6. Coupling electrochemical measurements with iridium dissolution studies under chemical or electrochemical conditions, we show that the deposition of an IrOxlayer on the surface of these perovskites is responsible for their OER activity. Furthermore, we experimentally reconstruct the iridium Pourbaix diagram, which will help guide future research in controlling the dissolution/precipitation equilibrium of iridium species for the design of better Ir‐based OER catalysts.
Institutions: Centre National de la Recherche Scientifique, Collège de France, Réseau sur le Stockage Electrochimique de l'énergie, Chimie du Solide et Energie, Sorbonne Université, Chimie de la Matière Condensée de Paris, Université Pierre-et-Marie-Curie, Université de Montpellier, Institut Charles Gerhardt Montpellier, Université Montpellier 2, Chimie ParisTech - PSL, Université Paris Sciences et Lettres, Institut de Recherche de Chimie Paris
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: green
Awards: G102163711, G107546177, G1286251239, G1313983767, G1664757510, G2287611682, G262962599, G3075337988, G426311843, G498139845, G5055290704, G5387317844, G6803667113, G6848031779, G6918803902, G7583137537, Mastering the electrochemical interfaces for developing improved water splitting electrocatalysts, G969889393, G993149817
OpenAlex ID: W2912044925