Atomically Dispersed High-Density Al-N₄ Sites in Porous Carbon for Efficient Photodriven CO₂ Cycloaddition

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Developing efficient catalysts for carbon dioxide (CO2) utilization powered by renewable energy is crucial for sustainable chemical processes.
• Photodriven CO2 cycloaddition reactions offer a promising route for CO2 value-added applications, but require highly active catalysts.

Purpose of the Study:

• To design and synthesize a highly active catalyst for efficient photodriven CO2 cycloaddition reactions.
• To investigate the catalytic performance of atomically dispersed aluminum-nitrogen-carbon (Al-N-C) sites under light irradiation.

Main Methods:

• A molecule-confined pyrolysis strategy was employed to create porous carbon nanosheets with a high loading of atomically dispersed Al atoms coordinated with N (AlN4 motif).
• The synthesized Al-N-C catalyst was tested for CO2 cycloaddition reactions under both light irradiation and thermal conditions.
• Experimental and theoretical analyses were conducted to elucidate the reaction mechanism and the role of light.

Main Results:

• The Al-N-C catalyst demonstrated significantly superior performance under light irradiation (95% conversion, 3.52 mmol g⁻¹ h⁻¹) compared to thermal conditions (57% conversion, 2.11 mmol g⁻¹ h⁻¹).
• The carbon matrix facilitated efficient photothermal conversion.
• Light irradiation promoted photogenerated electron transfer from the Al-N-C catalyst to the epoxide, facilitating the rate-limiting step.

Conclusions:

• The developed Al-N-C catalyst is highly effective for photodriven CO2 cycloaddition reactions, showcasing the potential of atomically dispersed metal-nitrogen-carbon sites.
• This study provides valuable insights into the design of advanced photocatalysts for heterogeneous catalysis, utilizing renewable energy for CO2 conversion.