Defect-Rich Porous Cu with Abundant Cu(100) for Acidic CO₂ Electroreduction in Membrane Electrode Assembly

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Acidic electrocatalytic CO2 reduction (CO2RR) is hindered by slow C-C coupling and hydrogen evolution, limiting C2+ product yields.
• Developing efficient catalysts is crucial for converting CO2 into valuable chemicals.

Purpose of the Study:

• To design and investigate porous copper nanosheets (pCu NS) for enhanced acidic CO2RR to C2+ products.
• To understand the catalytic mechanisms enabling efficient CO2 conversion.

Main Methods:

• Synthesis of porous copper nanosheets (pCu NS) with exposed Cu(100) facets and defect sites.
• Electrocatalytic performance evaluation in a membrane electrode assembly (MEA).
• In situ Raman spectroscopy and density functional theory (DFT) calculations to elucidate reaction mechanisms.

Main Results:

• pCu NS electrodes achieved 75.01% Faradaic efficiency for C2+ products at 300 mA cm-2.
• High CO2 single-pass conversion efficiency of up to 74.38% was observed.
• Mechanism revealed synergistic effects of nanopores, defects, and Cu(100) facets, creating an alkaline microenvironment and promoting *CO intermediate pathways.

Conclusions:

• pCu NS effectively promotes acidic CO2RR to C2+ products by optimizing intermediate binding and hydrogenation.
• The catalyst design offers a promising strategy for efficient CO2 conversion in acidic media.
• This research provides key insights for developing advanced electrocatalysts for CO2 utilization.