Cascade Dual Sites Modulate Local CO Coverage and Hydrogen-Binding Strength to Boost CO₂ Electroreduction to Ethylene

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrochemical CO2 reduction is crucial for sustainable chemical production.
• Controlling intermediate binding on copper catalysts is key for C-C coupling to multicarbon products.
• Developing efficient catalysts for ethylene (C2H4) production remains a challenge.

Purpose of the Study:

• To investigate the use of silver-copper (Ag-Cu) dual sites for enhancing C-C coupling in electrochemical CO2 reduction.
• To design and synthesize a novel catalyst with cascade Ag-Cu dual sites.
• To elucidate the atomic-scale mechanism for improved C2H4 generation.

Main Methods:

• Theoretical calculations (e.g., DFT) to understand reaction mechanisms and intermediate binding.
• Synthesis of copper nitride-silver (Cu3N-Ag) nanocubes (NCs).
• Electrochemical measurements, including Faraday efficiency and partial current density.
• In situ spectroscopy to probe catalytic intermediates.

Main Results:

• Ag-Cu dual sites synergistically increase local CO coverage and lower the kinetic barrier for CO protonation.
• Cu3N-Ag NCs exhibit significantly enhanced C2H4 production compared to Cu3N NCs (7.8x Faraday efficiency, 9.0x partial current density).
• Experimental and theoretical data confirm Ag sites produce CO and Cu sites promote asymmetric C-C coupling to *COCHO.

Conclusions:

• Cascade catalysis using Ag-Cu dual sites is an effective strategy for boosting CO2 to multicarbon products.
• The Cu3N-Ag NC catalyst demonstrates high performance for ethylene production via electrochemical CO2 reduction.
• This work offers atomic-level insights into catalyst design for efficient C-C coupling in CO2 electroreduction.