Theoretical insights into layered IrO₂ for the oxygen evolution reaction

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• The oxygen evolution reaction (OER) is crucial for renewable energy technologies.
• Developing efficient electrocatalysts for OER remains a significant challenge.
• Layered Iridium Dioxide (IrO2) polymorphs are potential candidates for OER catalysis.

Purpose of the Study:

• To explore layered IrO2 polymorphs using density functional theory for OER.
• To identify active site motifs and understand their catalytic properties.
• To develop a data-driven geometric descriptor for predicting catalytic activity.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Exploration of various layered IrO2 polymorph structures.
• Analysis of geometric and electronic properties related to OER activity.

Main Results:

• Layer edges were identified as highly promising active sites for OER.
• These sites exhibit low theoretical overpotential.
• Structural flexibility, including torsional distortion, was observed, potentially breaking universal scaling relations.

Conclusions:

• Layered IrO2 polymorphs, particularly at their edges, are excellent candidates for OER electrocatalysis.
• Geometric descriptors can effectively predict catalytic activity.
• Understanding structural flexibility is key to designing advanced OER catalysts.