Electron-rich SnO₂ promote CO₂ activation for stable electrocatalytic CO₂ reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic CO2 reduction to formate is key for carbon neutralization.
• Hydrogen evolution reaction (HER) competes with CO2 reduction, limiting efficiency.
• Activating CO2 and managing intermediate adsorption are critical challenges.

Purpose of the Study:

• To develop a stable and efficient electrocatalyst for CO2 reduction to formate.
• To improve CO2 activation and suppress HER by modulating Sn atom charge density.
• To investigate the role of La2Sn2O7/SnO2 heterostructures in CO2RR.

Main Methods:

• Synthesis of La2Sn2O7/SnO2 heterostructures.
• Electrocatalytic performance testing for CO2 reduction reaction (CO2RR).
• In situ electrochemical attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) and theoretical calculations.

Main Results:

• The 5% La2Sn2O7/SnO2 catalyst achieved a 70.7% Faradaic efficiency for HCOOH at -0.9 V vs. RHE.
• Enhanced CO2 activation and *OCHO intermediate adsorption were observed.
• The catalyst demonstrated stable electrolysis for 39 hours, with stabilized Sn oxidation states.

Conclusions:

• Introducing La2Sn2O7 into SnO2 effectively modulates charge density, enhancing CO2RR.
• The heterostructure's grain boundaries and electron transport promote efficient CO2 reduction.
• This work presents a viable strategy for developing stable Sn-based electrocatalysts for CO2 utilization.