Partially oxidized atomic cobalt layers for carbon dioxide electroreduction to liquid fuel

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• CO2 electroreduction offers a sustainable route to fuels, mitigating climate change.
• Activating CO2 typically requires high overpotentials, hindering practical application.
• Oxide-derived metal nanostructures show promise for efficient CO2 reduction.

Purpose of the Study:

• To investigate the influence of native oxides on the electrocatalytic activity of cobalt for CO2 reduction.
• To elucidate the role of interfaces and defects in CO2 reduction.
• To develop highly active and selective electrocatalysts for CO2 conversion.

Main Methods:

• Fabrication of atomically thin layers of pure cobalt metal and co-existing cobalt metal/oxide domains.
• Electrochemical evaluation of CO2 reduction activity, selectivity, and stability.
• Comparison of catalytic performance between atomically thin layers and bulk samples.

Main Results:

• Atomically thin cobalt layers exhibit higher intrinsic activity and formate selectivity than bulk cobalt.
• Partial oxidation of cobalt layers further enhances catalytic performance.
• Achieved stable current densities of 10 mA/cm² with 90% formate selectivity at 0.24 V overpotential.

Conclusions:

• Tailoring morphology and oxidation state transforms inactive materials into efficient CO2 electroreduction catalysts.
• Understanding atomic-scale structure and oxide presence is key to improving metal-based CO2 electrocatalysts.
• Demonstrated a highly efficient and stable electrocatalyst for CO2 to formate conversion.