Modulating Activity through Defect Engineering of Tin Oxides for Electrochemical CO₂ Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Environmental Science

Background:

• Electrochemical reduction of carbon dioxide (CO2) is a key strategy for mitigating climate change.
• Developing active, cost-effective, and scalable electrocatalysts is crucial for large-scale CO2 conversion.
• Current limitations include the lack of efficient catalysts for bulk production.

Purpose of the Study:

• To develop and characterize tin dioxide (SnO2) nanoparticles synthesized via flame spray pyrolysis (FSP) as electrocatalysts for CO2 reduction.
• To investigate the role of oxygen hole centers (OHCs) in SnO2 catalysts for CO2 activation.
• To demonstrate a scalable method for producing efficient CO2 reduction reaction (CO2RR) catalysts.

Main Methods:

• Synthesis of SnO2 nanoparticles using the industrially relevant flame spray pyrolysis (FSP) technique.
• Electrochemical characterization of SnO2 catalysts for CO2 reduction to formate.
• Manipulation of flame synthesis conditions to control the concentration of oxygen hole centers (OHCs).

Main Results:

• FSP-synthesized SnO2 nanoparticles exhibited high activity for CO2 conversion to formate (HCOO-).
• Achieved a Faradaic efficiency (FE) for formate of 85% at a current density of -23.7 mA cm-2 and -1.1 V vs RHE.
• Demonstrated that tuning OHC concentration directly impacts CO2 activation and catalytic performance.

Conclusions:

• Scalable FSP synthesis enables the rational design of highly active SnO2 electrocatalysts for CO2 reduction.
• Controlled defect engineering, specifically OHCs, is a viable strategy for enhancing CO2RR catalyst performance.
• This approach provides an ideal pathway for developing cost-effective catalysts for industrial CO2 utilization.