Modeling surface spin polarization on ceria-supported Pt nanoparticles

Area of Science:

• Materials Science
• Surface Science
• Catalysis

Background:

• Cerium oxide (CeO2) is a crucial material in catalysis, particularly as a support for metal nanoparticles.
• Understanding the electronic properties of the CeO2 surface is essential for optimizing catalytic activity.

Purpose of the Study:

• To investigate the phenomenon of spin polarization on the CeO2-(111) surface.
• To determine the impact of this spin polarization on the interaction between ceria and platinum (Pt) nanoparticles.
• To assess the effect on CO oxidation catalysis.

Main Methods:

• Density functional theory (DFT) simulations were employed.
• Gaussian type orbital basis sets were utilized.
• Calculations focused on surface spin polarization, oxygen vacancy formation energy, and adsorption energies.

Main Results:

• The CeO2-(111) surface exhibits robust spin polarization due to charge transfer between Ce and O layers.
• Spin polarization lowers the oxygen vacancy formation energy, enhancing ceria reducibility.
• It significantly reduces the activation barrier for CO oxidation on Pt/CeO2 catalysts.
• Surface spin polarization strengthens Pt-ceria bonding, though CO adsorption weakens this interaction.

Conclusions:

• Surface spin polarization is a key factor influencing the catalytic properties of CeO2.
• The findings suggest potential for designing advanced catalysts by controlling surface magnetism.
• Further experimental and theoretical studies on transition metal oxide surface ferromagnetism are warranted.