Atomically Isolated Cd Sites Boosting CO Electroreduction to C₂₊ Alcohols at Ampere-Level Current Densities

Area of Science:

• Electrocatalysis
• Materials Science
• Sustainable Chemistry

Background:

• Electrochemical CO2 reduction reaction (CORR) is crucial for converting CO2 into valuable chemicals.
• Developing efficient electrocatalysts for C-C coupling to C2+ alcohols remains a significant challenge.
• Copper-based electrocatalysts are promising but often suffer from low selectivity and efficiency.

Purpose of the Study:

• To investigate the mechanism of C-C coupling to C2+ alcohols in CORR using Cu-based model electrocatalysts.
• To design and evaluate Cu nanosheets modified with Cd single atoms (Cd-SACs@Cu NS) for enhanced CORR performance.
• To elucidate the role of single Cd atoms in promoting selectivity towards C2+ alcohols.

Main Methods:

• Rational design and synthesis of Cd-SACs@Cu NS and unmodified Cu NS electrocatalysts.
• Electrochemical performance evaluation in a flow cell under alkaline conditions.
• In situ characterization techniques and theoretical calculations (DFT) to study reaction mechanisms.

Main Results:

• Cd-SACs@Cu NS demonstrated significantly enhanced Faradaic efficiency (FE) for C2+ alcohols (nearly 70%) at a high current density (1100 mA cm-2).
• High FE (>50%) for C2+ alcohols was maintained over a broad current density range (100-2100 mA cm-2).
• Unmodified Cu NS primarily produced C2H4 via C-O bond cleavage.

Conclusions:

• Atomically dispersed Cd sites on Cu NS improve H2O dissociation and CO adsorption, promoting C2+ alcohol selectivity.
• Synergistic effects between Cd and Cu facilitate hydrogen spillover and intermediate protonation, crucial for C2+ alcohol formation.
• Cd-SACs@Cu NS represent a highly efficient electrocatalyst for selective C2+ alcohol production via CORR.