Probing the stability of SrIrO3 during active water electrolysis via operando atomic force microscopy

Mechanistic studies of oxide electrocatalysts for heterogeneous water oxidation have been primarily focused on understanding the origins of activity, with fewer studies addressing fundamental properties that influence stability. The main challenge is directly observing and quantifying local structur...

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Bibliographic Details
Published inEnergy & environmental science Vol. 16; no. 2; pp. 513 - 522
Main Authors Akbashev, Andrew R, Roddatis, Vladimir, Baeumer, Christoph, Liu, Tianchi, J Tyler Mefford, Chueh, William C
Format Journal Article
LanguageEnglish
Published Cambridge Royal Society of Chemistry 16.02.2023
Subjects
Atomic force microscopy
Corrosion
Corrosion rate
Degradation
Dissolution
Dynamic stability
Electric potential
Electrocatalysts
Electrochemistry
Electrolysis
Leaching
Microscopy
Oxidation
Oxides
Oxygen evolution reactions
Perovskites
Strontium
Structural stability
Surface stability
Transition metals
Voltage
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Summary:Mechanistic studies of oxide electrocatalysts for heterogeneous water oxidation have been primarily focused on understanding the origins of activity, with fewer studies addressing fundamental properties that influence stability. The main challenge is directly observing and quantifying local structural instability under operating conditions. In this work, we provide a dynamic view of the perovskite stability as a function of time and operational voltage using operando electrochemical atomic force microscopy (EC-AFM). Specifically, we study the degradation pathways of SrIrO3, a highly active electrocatalyst, during the oxygen evolution reaction (OER) by tracking the potential-dependent Sr leaching and perovskite dissolution at the nanometer scale. This material serves as a model system for degradation studies of perovskite AMO3 oxides, exhibiting both A-cation leaching and transition metal (M) dissolution. We show that Sr leaching precedes perovskite dissolution by up to 0.8 V, leading to a wide voltage window of stability where water oxidation occurs on a Sr-depleted surface without significant corrosion. Moreover, we reveal that the stability of the perovskite surface is strongly influenced by the electrolytic environment and that corrosion rates differ dramatically as a function of dissolved Sr concentration. Ultimately, our study demonstrates that the overall stability of perovskite oxides during electrocatalysis can be substantially improved by suppressing A-site leaching.
ISSN:1754-5692
1754-5706
DOI:10.1039/d2ee03704a