Regulating the electronic structure through charge redistribution in dense single-atom catalysts for enhanced alkene...

Area of Science:

• Materials Science
• Catalysis
• Surface Chemistry

Background:

• Inter-site interactions in single-atom catalysts (SACs) are critical for tuning electronic structure and catalytic performance.
• Densely populated SACs offer unique opportunities for enhanced reactivity due to synergistic effects.

Purpose of the Study:

• To develop a general synthesis strategy for densely populated SACs.
• To investigate the impact of cobalt (Co) loading on the electronic structure and catalytic performance in alkene epoxidation.
• To elucidate the relationship between catalyst density and catalytic efficiency.

Main Methods:

• Facile synthesis of densely populated Co SACs with varying loadings.
• Catalytic testing of trans-stilbene epoxidation using O₂.
• Theoretical studies (e.g., Bader charge, d-band center analysis) to understand electronic structure modifications.

Main Results:

• Significant enhancement in turnover frequency (10x) and mass-specific activity (30x) with increasing Co loading (5.4 wt% to 21.2 wt%).
• Electronic structure modification in densely populated Co atoms, characterized by reduced Bader charge and a higher d-band center.
• Demonstrated correlation between increased Co density, altered electronic properties, and improved O₂ and trans-stilbene activation.

Conclusions:

• Site interactions in densely populated SACs are crucial for regulating electronic structure and catalytic activity.
• Catalyst density is a key parameter for optimizing alkene epoxidation performance.
• Findings provide insights into designing high-performance SACs for epoxidation reactions.