Dynamic Restructuring of Cu₇S₄/Cu for Efficient CO₂ Electro-reduction to Formate

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical CO2 reduction (CO2RR) is a promising technology for converting CO2 into valuable chemicals.
• Optimizing catalyst properties, such as surface structure and reactant adsorption, is crucial for enhancing CO2RR efficiency.
• Sulfur doping in copper-based catalysts has shown potential for improving CO2RR performance.

Purpose of the Study:

• To develop a highly effective catalyst for electrochemical CO2 reduction to formate.
• To investigate the role of in-situ dynamic restructuring and sulfur doping in enhancing catalytic activity.
• To understand the mechanism by which the catalyst promotes formate production and suppresses hydrogen evolution.

Main Methods:

• In-situ dynamic restructuring of Cu7S4/Cu to form S-Cu2O/Cu hybrid catalyst.
• Electrochemical CO2 reduction (ECR) experiments.
• Thermodynamic analysis and in-situ Raman spectroscopy.

Main Results:

• The S-Cu2O/Cu hybrid catalyst significantly outperformed pure Cu2O/Cu and Cu7S4 catalysts in converting CO2 to formate.
• Sulfur doping optimized the adsorption of the formate intermediate (HCOO*) and suppressed the competing hydrogen evolution reaction (HER).
• Cu7S4/Cu nanoflowers provided abundant active sites and enhanced CO2 adsorption.

Conclusions:

• In-situ dynamic restructuring and sulfur doping are effective strategies for designing advanced electrocatalysts for CO2 reduction.
• The S-Cu2O/Cu catalyst offers a new pathway for efficient and selective electrochemical conversion of CO2 to formate.
• This work provides insights into catalyst design for various electrocatalytic reduction processes.