Local Coordination Environment-Driven Structural Dynamics of Single-Atom Copper and the CO₂ Electroreduction Pathway.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Structural stability of single-atom catalysts (SACs) is crucial for their application but remains a challenge.
• Understanding *operando* structural dynamics is key to linking SAC structure with activity and improving catalyst design.

Purpose of the Study:

• To investigate the coordination-driven structural dynamics of copper (Cu) single atoms in complexes.
• To explore the interaction of these dynamics with the electrochemical CO2 reduction (CO2R) pathway.
• To elucidate how ligand environments affect Cu SAC reconfiguration and CO2R product selectivity.

Main Methods:

• Utilized five well-defined mononuclear copper complexes with varied ligand structures.
• Studied *operando* structural dynamics and their influence on electrochemical CO2 reduction.
• Analyzed the role of coordination environments on binding energy and charge distribution.

Main Results:

• Coordination environments significantly impact Cu SAC reconfiguration by altering Cu-ligand binding energy and charge distribution.
• In situ reconstructed Cu(0) and Cu(I) sites serve as active centers for carbon product formation.
• Cu(0) sites correlate with CH4 generation, while a Cu(I)N3H-*CO intermediate promotes multicarbon products via *CO transfer.

Conclusions:

• Coordination environments critically influence product distribution in CO2R by modulating SAC reconfiguration.
• This work provides theoretical insights for designing stable Cu SACs with tunable CO2R selectivity.
• Understanding dynamic structural changes is essential for advancing SAC technology.