Regulating C-C Coupling via CO Generation and Utilization in CO₂RR on Ag-Cu Catalysts

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical CO2 reduction reaction (CO2RR) is crucial for sustainable chemical synthesis.
• Tandem catalysis using Ag-Cu systems offers a promising route to enhance selectivity for C2+ products.
• Controlling Cu oxidation states and surface structures is key to optimizing CO2RR performance.

Purpose of the Study:

• To design and investigate Ag@Cu2O, Ag@CuO, and Ag@CuO-BDC core-shell catalysts.
• To understand how these catalysts regulate CO generation, Cu oxidation states, and surface structures for CO2RR.
• To enhance selectivity towards C2+ products, particularly ethylene (C2H4), in CO2RR.

Main Methods:

• Synthesis of Ag@Cu2O, Ag@CuO, and Ag@CuO-BDC core-shell catalysts.
• Electrochemical characterization including Faradaic efficiency and partial current density measurements.
• Structural and chemical state analysis of the catalysts.

Main Results:

• Ag@Cu2O catalysts demonstrated significant tandem effects, suppressing methane (CH4) and enhancing C-C coupling.
• Ag@Cu2O-30 achieved a C2H4/CH4 ratio of 6.5 and a C2H4 partial current density of 12.3 mA cm-2 at -1.8 V.
• Ag@CuO catalysts improved CO/CO2 diffusion and reduced H2 formation; MOF-derived catalysts enhanced C2H4 selectivity but increased CH4 formation.

Conclusions:

• Ag-Cu tandem catalysis is an effective strategy for selective CO2 reduction to C2+ products.
• Structural engineering of Cu species in core-shell catalysts is vital for optimizing CO2RR.
• Further research into catalyst design can lead to improved ethylene production efficiency and selectivity.