Unlocking Copper-Free Interfacial Asymmetric C-C Coupling for Ethylene Photosynthesis from CO₂ and H₂O

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Solar-driven CO2 reduction to C2+ products like ethylene is key for carbon neutrality.
• Current methods often rely on copper-based catalysts and face challenges in efficiency and selectivity due to sluggish electron transfer and C-C coupling.
• Developing efficient, selective, and sustainable catalysts for CO2 photoreduction is crucial.

Purpose of the Study:

• To design a novel photocatalyst for efficient and selective solar-driven CO2 reduction to ethylene.
• To achieve high performance without using copper, noble metals, or sacrificial agents.
• To elucidate the mechanism of asymmetric C-C coupling facilitated by interfacial defects.

Main Methods:

• Fabrication of a sulfur-vacancy-rich MoS2/Fe2O3 photocatalyst sheet.
• Investigation of interfacial defect engineering for tandem catalytic centers.
• Characterization of the catalyst's electronic structure and catalytic performance for CO2 photoreduction.
• Analysis of reaction intermediates and C-C coupling mechanisms.

Main Results:

• The MoS2/Fe2O3 photocatalyst achieved a solar-to-chemical efficiency of 0.565% for CO2 to ethylene conversion.
• Superior selectivity of 84.9% for ethylene production was obtained.
• The catalyst demonstrated robust performance without copper, noble metals, or sacrificial agents.
• Interfacial S vacancies created a Z-scheme band alignment and a nitrogenase-analogous Mo-Fe heteronuclear unit, facilitating asymmetric C-C coupling.

Conclusions:

• The developed MoS2/Fe2O3 photocatalyst offers a promising copper-free and noble metal-free route for efficient CO2 photoreduction to ethylene.
• Interfacial defect engineering is a viable strategy to enhance electron transfer and C-C coupling for CO2 conversion.
• This work provides a new platform for designing advanced catalysts for C2+ synthesis from CO2 and H2O.