Defect engineering-driven enhancement of C₂₊ products over FeCN-modified cu for acidic CO₂ electroreduction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Acidic electrochemical CO2 reduction (CO2RR) is crucial for converting CO2 into valuable C2+ products.
• Challenges include competing hydrogen evolution reaction (HER) and slow carbon-carbon coupling.
• Developing efficient catalysts is essential for industrial CO2 utilization.

Purpose of the Study:

• To engineer defects in copper catalysts using Fe-doped carbon nitride (FeCN) for enhanced acidic CO2RR.
• To improve C2+ product selectivity and efficiency by reducing Cu defect formation energy.
• To investigate the mechanism of defect engineering on catalyst performance.

Main Methods:

• Synthesis of magnetron-sputtered Cu nanoparticle (MSCu) catalyst modified with FeCN (MSCu-FeCN).
• Evaluation of catalyst performance in a membrane electrode assembly (MEA) under acidic conditions.
• Utilizing Density Functional Theory (DFT) calculations, cyclic voltammetry, and in-situ ATR-FTIR spectroscopy for mechanistic studies.

Main Results:

• MSCu-FeCN achieved 73.07% C2+ Faradaic efficiency and 57.30% single-pass CO2 conversion efficiency at 500 mA·cm-2.
• The catalyst demonstrated significantly improved performance compared to the unmodified MSCu.
• FeCN modification lowered Cu defect formation energy, increased defect density, and enhanced *CO intermediate coverage.

Conclusions:

• Defect engineering via FeCN modification is an effective strategy for high-efficiency acidic CO2RR.
• The enhanced performance is attributed to improved CC coupling kinetics and reduced HER.
• This approach offers insights for designing advanced electrocatalytic systems for CO2 utilization.