Optimum Particle Size for Gold-Catalyzed CO Oxidation

Area of Science:

• Computational chemistry
• Surface science
• Catalysis

Background:

• Gold nanoparticles are effective catalysts for CO oxidation.
• Catalyst performance is influenced by particle size and structure.
• Understanding structure-activity relationships is crucial for catalyst optimization.

Purpose of the Study:

• To investigate the structure sensitivity of gold-catalyzed CO oxidation.
• To determine the dependence of CO oxidation rate on gold particle size and structure.
• To identify key descriptors for predicting catalytic activity.

Main Methods:

• First-principles microkinetics simulations.
• Analysis of CO and O2 adsorption properties.
• Identification of linear scaling relationships between reaction barriers and binding strengths.

Main Results:

• Planar gold clusters (<14 atoms) and 3D clusters (>14 atoms) exhibit distinct adsorption properties and scaling relationships.
• Planar Au9 and 3D Au79 clusters show the highest CO oxidation rates for their respective structures.
• Optimal performance is achieved with intermediate binding strengths, leading to intermediate surface coverages.

Conclusions:

• Catalytic activity of gold nanoparticles in CO oxidation is strongly structure-sensitive.
• Planar Au9 demonstrates significantly higher activity than the optimal 3D cluster (Au79).
• There is substantial room for improving gold catalysts for CO oxidation beyond current optimal configurations.