Potential Alignment in Tandem Catalysts Enhances CO₂-to-C₂H₄ Conversion Efficiencies.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Copper-based catalysts are limited by low CO coverage for selective C2H4 generation in CO2 electroreduction.
• Mismatches between CO-formation and C-C coupling catalysts hinder tandem electrocatalyst efficiency.

Purpose of the Study:

• To develop a robust tandem electrocatalyst for enhanced selective C2H4 generation from CO2.
• To address the catalyst component mismatch issue in CO2 electroreduction.

Main Methods:

• Theoretical calculations guided the selection of a nickel single atom catalyst (Ni SAC).
• In situ IR spectroscopy confirmed catalyst performance.
• Electrochemical testing in a flow-cell reactor evaluated C2H4 generation.

Main Results:

• The Ni SAC supported on Cu demonstrated a wide CO generation-potential window.
• Achieved a partial current density of ~370 mA/cm2 for C2H4 with ~62% faradaic efficiency.
• Maintained stable performance for over 14 hours at 500 mA/cm2 in a flow cell.

Conclusions:

• The proposed Ni SAC/Cu tandem catalyst effectively facilitates carbon dimerization for high-efficiency C2H4 production.
• This catalyst design overcomes previous limitations in CO2 electroreduction tandem systems.
• The demonstrated performance surpasses most previously reported tandem catalysts.