Interfacial Electronic Interaction in Amorphous-Crystalline CeO_x-Sn Heterostructures for Optimizing CO₂ to Formate...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Formate is a key raw material for industrial applications derived from carbon dioxide electroreduction (CO₂RR).
• Existing CO₂RR methods face challenges like low selectivity and formation rates due to competing hydrogen evolution reaction (HER) and high energy barriers for *OCHO intermediate generation.

Purpose of the Study:

• To develop a novel catalyst for efficient CO₂ electroreduction to formate.
• To investigate the catalytic performance and mechanism of amorphous-crystalline CeO_x-Sn heterostructures for CO₂RR.

Main Methods:

• A one-step chemical co-reduction strategy was used to synthesize amorphous-crystalline CeO_x-Sn heterostructures.
• Electrochemical performance was evaluated, including current density and Faraday efficiency for formate production.
• Density functional theory (DFT) calculations were employed to understand the catalytic mechanism.

Main Results:

• The optimized CeO_x-Sn heterostructures achieved a high current density of 265.1 mA cm^-2 and 95% formate Faraday efficiency at -1.07 V vs RHE.
• At -1.67 V vs RHE, CeO_x-Sn demonstrated a formate current density of 444.4 mA cm^-2 and a production rate of 9211.8 µmol h^-1 cm^-2.
• DFT calculations revealed that interface interactions between CeO_x and Sn optimize the electronic structure, facilitating electron transfer and lowering the *OCHO intermediate energy barrier.

Conclusions:

• The amorphous-crystalline CeO_x-Sn heterostructure exhibits remarkable catalytic performance for CO₂ electroreduction to formate.
• The optimized interface and electronic structure are crucial for enhancing CO₂RR efficiency and selectivity.
• This work provides a promising strategy for designing advanced catalysts for CO₂ conversion.