Interface Engineering of Gold Nanoclusters for CO Oxidation Catalysis

Area of Science:

• Heterogeneous catalysis
• Nanomaterials science
• Surface chemistry

Background:

• Atomically precise gold nanoclusters offer model systems for structure-activity relationships in catalysis.
• Understanding ligand effects and interface phenomena is crucial for optimizing nanocluster catalyst performance.
• Carbon monoxide (CO) oxidation is a key probe reaction for evaluating catalytic activity.

Purpose of the Study:

• To investigate the interface effects of ligand-protected gold nanoclusters (Au38(SR)24, Au36(SR')24, Au25(SR″)18) on CO oxidation.
• To elucidate the role of ligand steric hindrance versus carbon tail bulkiness in catalytic activity.
• To compare the thermal pretreatment sensitivity of different gold nanocluster structures (icosahedral vs. face-centered cubic).

Main Methods:

• Synthesis and characterization of three series of ligand-protected gold nanoclusters.
• Evaluation of catalytic activity for CO oxidation using the gold nanoclusters as catalysts.
• Systematic variation of ligand structures and thermal pretreatment conditions.

Main Results:

• Steric hindrance of ligands at the gold-ceria dioxide (CeO2) interface, rather than ligand carbon tail bulkiness, inhibits CO adsorption and reduces catalytic activity.
• Au36(SR')24 nanoclusters (face-centered cubic) exhibit insensitivity to thermal pretreatment.
• Au38(SR)24 catalysts (icosahedral) show sensitivity to thermal pretreatment, with optimal activity at 150 °C.

Conclusions:

• Atomically precise gold nanoclusters provide detailed insights into catalytic interface and atomic structure effects.
• Ligand design and structural properties significantly influence catalytic performance.
• Findings will aid in the future design of highly efficient, environmentally friendly catalysts.