Restructuring multi-phase interfaces from Cu-based metal-organic frameworks for selective electroreduction of CO₂ to...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical CO2 reduction is crucial for sustainable energy, but faces challenges in interfacial engineering and mechanism understanding.
• Multi-phase interfaces offer potential for overcoming energy barriers in multi-electron transfer reactions like CO2 reduction.

Purpose of the Study:

• To develop and investigate highly active Ag/Cu/Cu2O heterostructures for efficient electrochemical CO2 reduction to ethylene.
• To elucidate the role of interfacial micro-structures and dynamic changes in the working mechanism of CO2 reduction catalysts.

Main Methods:

• In situ electrochemical restructuring of Ag-incorporating HKUST-1 (a metal-organic framework) to form Ag/Cu/Cu2O heterostructures.
• Electrochemical CO2 reduction experiments in flow cells.
• In/ex situ characterizations and theoretical calculations to analyze interfacial properties and reaction mechanisms.

Main Results:

• Achieved efficient CO2-to-C2H4 conversion with high faradaic efficiency (57.2% at -1.3 V vs. RHE) and good stability.
• Demonstrated that Ag stabilizes Cu(I) and enhances CO surface coverage.
• Identified active Cu/Cu2O interfaces as key to reducing the C-C coupling energy barrier for ethylene production.

Conclusions:

• Metal-organic frameworks are effective precursors for in-situ derivation of efficient electrocatalysts.
• The study provides atomic-level understanding of the working interfaces in electrochemical CO2 reduction.
• The developed Ag/Cu/Cu2O heterostructures represent a significant advancement in CO2-to-C2H4 conversion catalysis.