Highly active and stable surface structure for oxygen evolution reaction originating from balanced dissolution and...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Oxygen evolution reaction (OER) is critical for water electrolyzers but is limited by catalyst stability, especially in acidic media.
• Barium iridate (BaIrO3) shows promise but suffers from lattice collapse during OER, hindering durability.
• Acidic OER is preferred for high current densities and preventing carbonate precipitation.

Purpose of the Study:

• To develop a highly active and stable OER catalyst for acidic conditions.
• To overcome the lattice collapse issue in BaIrO3 during OER cycling.
• To improve the durability and efficiency of water electrolyzers for hydrogen production.

Main Methods:

• Synthesized manganese-substituted barium iridate (BaIr1-xMnxO3).
• Investigated catalyst performance under acidic OER conditions.
• Analyzed catalyst structure and stability after OER cycling.

Main Results:

• BaIr0.8Mn0.2O3 exhibited a 28-fold increase in activity and improved stability.
• The catalyst prevented lattice collapse by controlled elemental dissolution and surface reconstruction.
• Achieved mass activity ~73 times higher than IrO2, demonstrating superior performance.

Conclusions:

• Manganese substitution in BaIrO3 effectively enhances OER activity and stability in acidic media.
• The developed catalyst offers a sustainable and promising alternative for energy conversion technologies.
• Controlled dissolution and surface reconstruction are key to improving catalyst durability.