Dislocation-Induced Strain in Bismuth Nanoparticles for Improving Carbon Dioxide Electroreduction to Formic Acid

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical reduction of carbon dioxide (CO2) offers a pathway to sustainable formic acid production.
• Solid-electrolyte membrane electrode assembly (MEA) electrolyzers are promising for CO2 conversion.
• Optimizing cathode catalyst design is crucial for enhancing MEA electrolyzer performance.

Purpose of the Study:

• To design and investigate a novel catalyst for the cathode membrane electrode in solid-electrolyte MEA electrolyzers.
• To improve the efficiency and stability of formic acid production from CO2 electroreduction.

Main Methods:

• Fabrication of lattice strain-rich bismuth nanoparticles (D-Bi-NPS) integrated with an anion exchange membrane.
• Electrochemical testing of the D-Bi-NPS cathode in a solid-electrolyte MEA electrolyzer.
• Analysis of formic acid concentration, Faradaic efficiency, and operational stability.

Main Results:

• The D-Bi-NPS cathode enabled continuous formic acid production at 0.19 M concentration for over 74 hours at 100 mA cm-2.
• Achieved a maximum Faradaic efficiency of 94.1% for formic acid, with >80% maintained for most of the operation.
• Lattice strain and internal defects in D-Bi-NPS accelerated electron transfer and optimized intermediate adsorption.

Conclusions:

• The developed D-Bi-NPS catalyst significantly enhances formic acid production in solid-electrolyte MEA electrolyzers.
• Lattice strain engineering is an effective strategy for designing high-performance electrocatalysts.
• This work presents a novel approach for designing efficient solid-electrolyte MEA electrolyzers for CO2 conversion.