Carbon-coated bismuth catalyst for efficient and stable CO₂ electroreduction to formate

Area of Science:

• Catalysis
• Materials Science
• Electrochemistry

Background:

• Bismuth (Bi)-based catalysts are crucial for electrocatalytic CO2 reduction (ECR) to produce formate.
• Current Bi catalysts suffer from low activity and poor stability, limiting practical use.

Purpose of the Study:

• To investigate the effect of carbon coating on Bi catalysts for improved ECR performance.
• To understand the interaction between Bi particles and carbon support on catalytic activity and stability.

Main Methods:

• Preparation of carbon-supported Bi particles (Bi/C) and carbon-coated Bi particles (Bi@C) using ligand modulation of Bi-based metal-organic frameworks.
• Evaluation of catalytic activity, Faradaic efficiency for formate (FEformate), and long-term stability in acidic and alkaline electrolytes.

Main Results:

• The Bi@C catalyst demonstrated enhanced charge transfer and optimized reaction kinetics compared to Bi/C.
• Bi@C achieved higher current density and FEformate, with remarkable stability at 120 mA cm-2 in both pH 1.00 and 14.00 electrolytes.
• FEformate/FEformate (formic acid) remained above 90% for Bi@C, indicating high selectivity.

Conclusions:

• Carbon coating on Bi particles significantly improves electrocatalytic CO2 reduction activity and operational stability.
• The Bi@C catalyst shows great potential for efficient and durable industrial CO2 electroreduction.
• This study offers insights for designing advanced Bi-based ECR catalysts.