Exploring dopant effects in stannic oxide nanoparticles for CO₂ electro-reduction to formate

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrosynthesis of formate from carbon dioxide (CO₂) offers environmental benefits and economic value.
• Stannic oxide is a promising catalyst but suffers from metallic phase formation and reduced activity at high potentials.

Purpose of the Study:

• To develop a more active and durable catalyst for CO₂ electroreduction to formate.
• To investigate the role of fluorine doping in tin oxide catalysts.

Main Methods:

• Electrochemical testing of fluorine-doped tin oxide catalysts.
• In-situ/operando spectroscopy.
• First-principle calculations.

Main Results:

• Achieved 95% Faradaic efficiency for formate at 100 mA cm^-2.
• Reached a maximum partial current density of 330 mA cm^-2.
• Demonstrated stable formate selectivity (≈90%) over 7 days at 100 mA cm^-2.
• Spectroscopy and calculations confirmed fluorine's role in maintaining Sn oxidation state and surface stability.

Conclusions:

• Fluorine doping enhances the activity and durability of tin oxide electrocatalysts for CO₂ reduction.
• The doped catalyst maintains high oxidation states, crucial for performance at high current densities.
• This work presents an efficient strategy for designing advanced electrocatalysts for formate synthesis.