Dual-Site Activation for Efficient Acidic CO₂ Electroreduction at Industrial-Level Current Densities

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• CO₂ electroreduction to formic acid is key for CO₂ utilization.
• Achieving high formic acid selectivity in acidic media is difficult due to hydrogen evolution reaction (HER).
• Industrial application requires catalysts with high selectivity at high current densities.

Purpose of the Study:

• To develop a catalyst for enhanced CO₂ electroreduction to formic acid.
• To improve formic acid selectivity in acidic electrolytes.
• To investigate a charge redistribution modulation strategy using a Mott-Schottky catalyst.

Main Methods:

• Fabrication of CuS/SnS₂ Mott-Schottky heterostructure.
• Electrochemical characterization of CO₂ reduction reaction (CO₂RR).
• Density Functional Theory (DFT) calculations to understand reaction mechanisms.

Main Results:

• CuS/SnS₂ catalyst demonstrated significantly enhanced CO₂ adsorption and stabilization of key intermediates.
• Achieved a maximum formic acid Faradaic efficiency (FE) of 99% in acidic electrolytes.
• Maintained over 80% selectivity at a high current density of 1 A cm⁻², outperforming individual components.
• Showcased excellent selectivity across pH-universal electrolytes.

Conclusions:

• Charge redistribution modulation via CuS/SnS₂ Mott-Schottky catalyst effectively suppresses HER and enhances formic acid selectivity.
• Dual-site activation mechanism is crucial for efficient CO₂ electroreduction to formic acid.
• This strategy offers a promising pathway for designing advanced CO₂ reduction reaction (CO₂RR) catalysts.