Anionic Metal-Organic Framework Derived Cu Catalyst for Selective CO₂ Electroreduction to Hydrocarbons.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Metal-organic frameworks (MOFs) are promising for CO2 electroreduction (CO2RR).
• MOF restructuring under reaction conditions is crucial for catalyst design.
• Developing catalysts for multi-carbon (C2) product selectivity is essential.

Purpose of the Study:

• To fabricate an anionic HKUST-1 (a-HKUST-1) as a pre-catalyst.
• To investigate the electrochemical reduction of a-HKUST-1 into Cu-based catalysts.
• To achieve high selectivity for C2 products in alkaline CO2RR.

Main Methods:

• Facile solvent process for a-HKUST-1 synthesis.
• Electrochemical CO2 reduction in an alkaline electrolyte.
• In situ Raman spectroscopy for intermediate analysis.

Main Results:

• The a-HKUST-1 catalyst reconstructs into an active Cu catalyst (aHD-Cu) under operating conditions.
• aHD-Cu achieves a Faradaic efficiency (FE) for C2H4 of 56% and FE for C2 of ~80% at -150 mA cm-2.
• The catalyst exhibits high electrochemically active surface area and low-coordinated sites.

Conclusions:

• Exploiting MOF restructuring is key for designing efficient CO2RR catalysts.
• The aHD-Cu catalyst demonstrates excellent performance for C2 product generation.
• High *CO intermediate coverage on aHD-Cu favors hydrocarbon production.