Optimizing *CO/CO Supply by Atomically Dispersed Fe Sites for High-rate CO₂-to-C₂H₄ Conversion Under Visible Light

Area of Science:

• Catalysis
• Materials Science
• Renewable Energy

Background:

• Visible light-driven CO2 reduction to ethylene (C2H4) offers a sustainable route to fuels and chemicals.
• The primary limitation is the insufficient supply of CO intermediates, hindering C-C coupling for C2H4 formation.

Purpose of the Study:

• To develop a highly efficient catalyst for visible light-driven CO2 reduction to C2H4.
• To elucidate the mechanism by which the catalyst promotes C-C coupling and C2H4 generation.

Main Methods:

• Synergistic engineering of a Fe0.2/H-MOF-1 composite catalyst with high-density iron single atom sites (Fe SAs).
• Characterization using X-ray absorption fine structure (XAFS).
• CO adsorption experiments and density functional theory (DFT) calculations.

Main Results:

• The Fe0.2/H-MOF-1 catalyst achieved an exceptional C2H4 yield of 1056.2 µmol·g-1·h-1 under visible light.
• Demonstrated superior performance compared to state-of-the-art systems.
• Identified Fe-N active sites that lower the energy barrier for *COOH to *CO conversion and enhance CO adsorption for C-C coupling.

Conclusions:

• The engineered Fe-N active sites effectively promote rapid C2H4 generation via photocatalytic CO2 reduction.
• This work provides critical insights for designing advanced catalysts for efficient visible light-driven CO2 reduction reactions.