Dynamic Stability of Copper Single-Atom Catalysts under Working Conditions

Area of Science:

• Catalysis
• Materials Science
• Electrochemistry

Background:

• Single-atom catalysts (SACs) show great promise but their long-term stability under working conditions is a significant challenge for commercialization.
• Current methods often fail to accurately assess the dynamic behavior of SACs during catalytic reactions.

Purpose of the Study:

• To develop and apply a dynamic model for evaluating the stability of single-atom catalysts under realistic working conditions.
• To elucidate the mechanism of reversible transformation between single copper atoms and copper clusters on N-doped graphene.

Main Methods:

• Utilized a "constant-potential hybrid-solvation dynamic model" to simulate catalyst behavior.
• Investigated the influence of electrode potential and hydrogen adsorption on copper single-atom stability.
• Analyzed the formation and role of transient copper clusters in CO2 reduction.

Main Results:

• Hydrogen adsorption was identified as a key factor driving the leaching of copper single atoms, especially at negative potentials.
• A dynamic cycle of copper atom leaching, cluster formation, CO2 reduction, and redeposition was observed.
• Transient copper clusters act as active sites for CO2 to ethanol conversion, with hydroxyl radicals mediating the return to atomic dispersion.

Conclusions:

• The study provides atomic-level insights into the dynamic stability and reconstruction cycle of copper single-atom catalysts.
• A reassessment of SAC stability is needed, considering dynamic transformations under realistic operating potentials and reaction environments.