Dynamic Interface Engineering via Mechanistic Understanding of Copper Reconstruction in Electrochemical CO₂ Reduction...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Improving C2+ selectivity in CO2 electroreduction is crucial for sustainable chemical synthesis.
• Copper catalysts are promising for CO2 electroreduction but require optimized active sites.
• Anodic pulse strategies are used to modify copper catalyst surfaces in situ, but mechanisms are unclear.

Purpose of the Study:

• To elucidate the distinct surface reconstruction mechanisms of copper under anodic potentials during CO2 electroreduction.
• To understand the impact of different reconstruction pathways on C2+ selectivity.
• To develop an energy-efficient strategy for sustained C2+ selectivity.

Main Methods:

• Applying anodic potentials to copper electrodes in CO2 electroreduction.
• Analyzing surface reconstruction via oxide formation and metal dissolution pathways.
• Implementing electrolyte engineering with trace Cu2+ ions under cathodic conditions.

Main Results:

• Anodic potentials induce two distinct copper reconstructions: oxide formation and metal dissolution.
• Oxide-derived reconstruction offers transient C2+ selectivity enhancement.
• Dissolution-redeposition reconstruction leads to continuous formation of C2-selective sites and progressive selectivity increase.
• Electrolyte engineering with trace Cu2+ under cathodic conditions activates the dissolution-redeposition pathway, enhancing selectivity without anodic bias.

Conclusions:

• Mechanistic understanding of copper surface reconstruction is key to controlling CO2 electroreduction selectivity.
• The dissolution-redeposition pathway provides a sustainable route to C2+ selective sites.
• Electrolyte engineering offers an energy-efficient alternative for dynamic electrochemical interfaces and controllable selectivity.