The role of surface spin polarization on ceria-supported Pt nanoparticles

TL;DR

This study uses first-principles simulations to reveal how surface spin polarization on ceria supports influences metal-support interactions and catalytic activity of Pt nanoparticles, notably reducing activation barriers in CO oxidation.

Contribution

It is the first to demonstrate the impact of surface spin polarization on ceria-supported Pt catalysts and their reaction pathways.

Findings

Surface spin polarization lowers oxygen vacancy formation energy.

Spin polarization enhances Pt-ceria surface bonding.

It reduces the activation barrier for CO oxidation.

Abstract

In this work, we employ first-principles simulations to investigate the spin polarization of CeO$_2$-(111) surface and its impact on interactions between a ceria support and Pt nanoparticles. For the first time, we report that the CeO$_2$-(111) surface exhibits a robust surface spin polarization due to the internal charge transfer between atomic Ce and O layers. In turn, it can lower the surface oxygen vacancy formation energy and enhance the oxide reducibility. We show that the inclusion of spin polarization can therefore significantly reduce the major activation barrier in the proposed reaction pathway of CO oxidation on ceria-supported Pt nanoparticles. For metal-support interactions, surface spin polarization enhances the bonding between Pt nanoparticle and ceria surface oxygen, while CO adsorption on Pt nanoparticles weakens the interfacial interaction regardless of spin polarization.