Atomic Interlayer Mo-N₄ Sites Enable Rapid Charge Transfer and Efficient CO₂ Photoreduction.

Area of Science:

• Materials Science
• Catalysis
• Photochemistry

Background:

• Photocatalytic CO2 reduction is crucial for sustainable carbon conversion.
• Efficiency is hindered by poor charge separation and limited active sites in current catalysts.

Purpose of the Study:

• To address limitations in photocatalytic CO2 reduction by designing a novel catalyst.
• To enhance charge separation and introduce functional active sites for improved efficiency.

Main Methods:

• Fabrication of an atomic Mo-N4 interlayer electron bridge (IEB) within a bipyridine-based covalent organic framework (COF) using photoreduction.
• Density Functional Theory (DFT) screening to identify molybdenum (Mo) as the optimal metal center.
• Characterization of the Mo@Tp-Bpy catalyst and evaluation of its performance in coupled CO2 reduction and oxidation reactions.

Main Results:

• The Mo@Tp-Bpy catalyst demonstrated high co-production rates: 948.0 µmol g⁻¹ h⁻¹ for CO and 3741.7 µmol g⁻¹ h⁻¹ for anisaldehyde.
• Achieved 6.2-fold and 5.0-fold enhancements in CO and anisaldehyde production, respectively, compared to the pristine COF.
• Mo-N4 sites were shown to facilitate interlayer charge kinetics and reduce thermodynamic barriers for catalytic half-reactions.

Conclusions:

• The atomic Mo-N4 IEB effectively integrates charge management and catalytic function in layered COF materials.
• This strategy offers a rational, atomic-level approach for developing highly efficient photoredox catalysts.
• The findings pave the way for advanced materials in sustainable carbon conversion technologies.