Construction of Bi-Sn(In)O Integrated Electrode for Efficient CO₂ Electroreduction to Formate

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Tin oxide (SnO2) shows promise for electrochemical formate synthesis from carbon dioxide (CO2).
• Existing methods face challenges with performance and mechanistic understanding.
• Developing efficient catalysts for CO2 reduction remains a critical research area.

Purpose of the Study:

• To develop an integrated electrode for enhanced electrochemical synthesis of formate from CO2.
• To optimize a hierarchical metal-metal oxide nanoarray catalyst.
• To elucidate the reaction mechanism for improved CO2 reduction.

Main Methods:

• Hydrothermal synthesis and electrodeposition were used to create a hierarchical metal-metal oxide nanoarray.
• An integrated electrode design eliminated the need for polymer binders.
• In situ infrared characterization and theoretical calculations were employed.

Main Results:

• The Bi-Sn(In)O electrocatalyst achieved 83.66% Faradaic efficiency for CO2 to formate conversion.
• A high production rate of 768.12 μmol·h⁻¹·cm⁻² was observed.
• The integrated electrode design and Snδ+ species enhanced the adsorption of the *OCHO intermediate.

Conclusions:

• Optimized SnO2 catalysts with high-valence Snδ+ species significantly improve formate production.
• The integrated electrode design enhances catalytic activity by increasing active sites.
• This work offers insights into catalyst design for efficient CO2 reduction.