Iridium Nanocrystals Enriched with Defects and Atomic Steps to Enhance Oxygen Evolution Reaction Performance.

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Defects in catalysts significantly impact activity and stability by altering reactant, intermediate, and product binding.
• Synthetically controlling defects in nanocrystal catalysts remains a significant challenge.

Purpose of the Study:

• To demonstrate precise control over the growth of iridium (Ir) nanocrystals.
• To tune both structural and surface defects in Ir nanocrystals for enhanced catalytic performance.
• To investigate the role of engineered defects in improving the oxygen evolution reaction (OER).

Main Methods:

• Controlled synthesis of Ir nanocrystals with varying structures, from single crystals to multiply twinned crystallites.
• Characterization of nanocrystal structures, including atomic steps and surface defects.
• Evaluation of catalytic performance for the oxygen evolution reaction (OER).

Main Results:

• Achieved tunable control over the growth of Ir nanocrystals, yielding diverse structures.
• Demonstrated that engineered structural and surface defects enhance catalytic activity and stability.
• Identified specific defect types correlating with improved OER performance.

Conclusions:

• Synthetic control over structural and surface defects in metal nanoparticles is a viable strategy for improving catalytic performance.
• Defect engineering in Ir nanocrystals offers a pathway to highly active and stable catalysts for reactions like OER.
• Understanding the precise role of defects is crucial for designing next-generation catalysts.