A Dissolution/Precipitation Equilibrium on the Surface of Iridium-Based Perovskites Controls Their Activity as Oxygen Evolution Reaction Catalysts in Acidic Media

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)O4 were explored as OER catalysts in acidic media. Their activities were observed to be roughly equal to those previously reported for La2LiIrO6 or Ba2PrIrO6. Coupling electrochemical measurements with iridium dissolution studies under chemical or electrochemical conditions, we show that the deposition of an IrOx layer 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.
Type de document :
Article dans une revue
Domaine :
Liste complète des métadonnées

Littérature citée [35 références]  Voir  Masquer  Télécharger

https://hal.umontpellier.fr/hal-02100661
Contributeur : Odile Hennaut <>
Soumis le : mercredi 17 avril 2019 - 13:55:30
Dernière modification le : mardi 28 mai 2019 - 14:06:15

Identifiants

Citation

Manel Ben osman, Moulayt Sougrati, Domitille Giaume, Alexis Grimaud, Ronghuan Zhang, et al.. A Dissolution/Precipitation Equilibrium on the Surface of Iridium-Based Perovskites Controls Their Activity as Oxygen Evolution Reaction Catalysts in Acidic Media. Angewandte Chemie International Edition, Wiley-VCH Verlag, 2019, 58 (14), pp.4571-4575. ⟨10.1002/anie.201814075⟩. ⟨hal-02100661⟩

Partager

Métriques

Consultations de la notice

54