High-Rate CO₂ Electroreduction to C₂₊ Products over a Copper-Copper Iodide Catalyst

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical CO2 reduction reaction (CO2 RR) is crucial for renewable energy storage and closing the carbon cycle.
• Producing multicarbon hydrocarbons and oxygenates (C2+ products) efficiently remains a significant challenge.

Purpose of the Study:

• To develop a highly effective catalyst for CO2 RR to C2+ products.
• To investigate the catalytic performance of a Cu-CuI composite material.

Main Methods:

• Fabrication of a Cu-CuI composite catalyst by physically mixing Cu nanoparticles and CuI powders.
• Electrochemical testing in a flow cell at -1.0 V vs. reversible hydrogen electrode using an alkaline electrolyte.
• Analysis of catalyst reconstruction and performance under CO2 RR conditions.

Main Results:

• The Cu-CuI composite catalyst achieved a remarkable C2+ partial current density of 591 mA cm−2, significantly outperforming individual Cu and CuI catalysts.
• Catalyst reconstruction occurred under reaction conditions, involving alkaline electrolyte and applied potential.
• The enhanced performance is attributed to Cu0/Cu+ interfaces, residual Cu+ species, and adsorbed iodine.

Conclusions:

• The Cu-CuI composite catalyst demonstrates superior performance for CO2 RR to C2+ products.
• The catalyst's structure and active sites play a critical role in facilitating C-C coupling and improving CO adsorption.
• This work presents a promising strategy for efficient carbon utilization and renewable energy conversion.