Retained Oxygen Regulation in Oxide-Derived Copper for Promoted CO₂ Electroreduction Toward Multicarbon Products

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical carbon dioxide reduction (CO2R) offers a pathway for renewable energy storage.
• Oxide-derived copper (OD-Cu) is promising for multicarbon (C2+) product selectivity.
• Controlling residual oxygen in OD-Cu during reconstruction is key but challenging.

Purpose of the Study:

• To investigate the role of thickness-dependent residual oxygen in OD-Cu for CO2R.
• To understand how oxygen retention influences C2+ selectivity.
• To optimize OD-Cu catalysts for efficient multicarbon production.

Main Methods:

• Synthesis of CuO nanosheets with varying thicknesses.
• Electrochemical CO2 reduction experiments.
• Long-time molecular dynamics simulations.
• Structural characterization (e.g., XPS, TEM) and electrochemical analysis.

Main Results:

• 1.6 nm CuO precatalysts retained optimal oxygen, enhancing C2+ selectivity.
• Faradaic efficiencies for C2+ products reached ~80% over a wide current density range (300-700 mA cm-2).
• Simulations showed enhanced Cu-CuO stability with increased oxygen removal, favoring C2+ pathways (*CHO formation and *OC-CHO coupling).

Conclusions:

• Residual oxygen plays a critical role in OD-Cu performance for CO2R.
• Optimized oxygen retention in reconstructed stacked nanosheets enhances C2+ product formation.
• This work provides insights for designing OD-Cu catalysts with improved oxygen management for efficient C2+ synthesis.