Highly stable and Active Cu₁ /CeO₂ Single-Atom Catalyst for CO Oxidation: A DFT Study

Area of Science:

• Materials Science
• Catalysis
• Surface Chemistry

Background:

• Single-atom catalysts (SACs) offer unique advantages in heterogeneous catalysis due to their maximum atom utilization efficiency.
• Cerium dioxide (CeO2) is a widely studied support material known for its oxygen storage capacity and redox properties.
• Understanding the stability and reactivity of single metal atoms on oxide supports is crucial for designing advanced catalysts.

Purpose of the Study:

• To investigate the stability and carbon monoxide (CO) oxidation activity of single copper (Cu) atoms supported on CeO2 (111).
• To elucidate the electronic structure and adsorption properties of CO on the Cu1/CeO2 system.
• To determine the catalytic mechanism for CO oxidation over this single-atom catalyst.

Main Methods:

• Density Functional Theory (DFT) simulations were employed to model the Cu1/CeO2 system.
• Calculations included binding energy, diffusion activation energy, and electronic structure analysis.
• Frequency analysis was used to interpret CO adsorption spectra.

Main Results:

• The Cu1/CeO2 single-atom catalyst demonstrates high stability, evidenced by strong binding energy and high diffusion activation energy for Cu atoms.
• Electronic structure analysis confirmed the formation of Cu+ cations due to electron transfer from CeO2 to Cu.
• Frequency analysis correlated experimental Infrared (IR) bands with Cu+-carbonyl species, confirming CO adsorption site.

Conclusions:

• The Cu1/CeO2 single-atom catalyst exhibits excellent stability and significant potential for CO oxidation.
• The catalytic activity proceeds via the Mars van Krevelen mechanism, involving the redox properties of the CeO2 support.
• This study provides fundamental insights into the structure-activity relationship of single-atom catalysts on oxide supports.