Activity-Stability Trends for the Oxygen Evolution Reaction on Monometallic Oxides in Acidic Environments

Area of Science:

• Materials Science
• Electrochemistry
• Surface Science

Background:

• The oxygen evolution reaction (OER) is crucial for many electrochemical energy technologies.
• Understanding the interplay between catalyst activity and stability is essential for OER catalyst development.
• Monometallic oxides are widely studied as potential OER electrocatalysts.

Purpose of the Study:

• To establish a functional link between the activity and stability of monometallic oxides during the OER in acidic media.
• To identify the key factors governing the activity-stability relationship in OER catalysts.
• To provide guidance for designing more effective OER electrocatalysts.

Main Methods:

• Surface-science approach to investigate monometallic oxides.
• Electrochemical measurements in acidic media to assess OER performance.
• Analysis of oxide nobility and surface defect density.

Main Results:

• A clear inverse relationship was observed: highly active oxides were least stable.
• Oxide nobility and surface defect density were identified as key controlling factors.
• Metal cation valence state transformations (n=+4 to n>+4) influence stability.
• Dissolution rates were found to be critically dependent on the metal cation's nature.

Conclusions:

• The most active OER catalysts in acid are inherently unstable.
• Optimizing OER performance requires a careful balance between catalytic activity and material stability.
• Future OER catalyst design should consider both nobility and defect engineering to mitigate dissolution.