Highly Stable and Reactive Platinum Single Atoms on Oxygen Plasma‐Functionalized CeO₂ Surfaces: Nanostructuring and Peroxo Effects

Abstract

Atomically dispersed precious metals on oxide supports have recently become increasingly interesting catalytic materials. Nonetheless, their non-trivial preparation and limited thermal and environmental stability constitutes an issue for their potential applications. Here we demonstrate that an oxygen plasma pre-treatment of the ceria (CeO 2 ) surface serves to anchor Pt single atoms, making them active and resistant towards sintering in the CO oxidation reaction. Through a combination of experimental results obtained on well-defined CeO 2 films and theory, we show that the O 2 plasma causes surface nanostructuring and the formation of surface peroxo (O 2 2À ) species, favoring the uniform and dense distribution of isolated strongly bonded Pt 2 + atoms. The promotional effect of the plasma treatment was further demonstrated on powder Pt/CeO 2 catalysts. We believe that plasma functionalization can be applied to other metal/oxide systems to achieve tunable and stable catalysts with a high density of active sites.

Single-Atom Catalysis: Insights from Model Systems

“…Color code: Ce, gold; O, red; Pt, green; peroxo O 2 2– , pink. Reproduced with permission from ref . Copyright 2022 Wiley-VCH GmbH under CC-BY license ().…”

Recent progresses on single-atom catalysts for the removal of air pollutants

“…The surface functionalization of CeO 2 can boost thermal stability and catalytic activity of Pt/CeO 2 in CO oxidation. The oxygen plasma pre-treatment on CeO 2 surface has been demonstrated to serve as an effective strategy ( Wan W. et al, 2022 ), which led to two crucial modifications of CeO 2 surface: 1) surface restructuring, surface roughening that suppressing the diffusion and aggregation of Pt atoms; 2) a significant amount of surface peroxide (O 2 2− ) powerfully anchoring Pt single atoms. These features are favor of a dense and uniform distribution of active Pt single atoms to boost CO oxidation.…”

Unravelling the correlation of dielectric barrier discharge power and performance of Pt/CeO2catalysts for toluene oxidation

“…26,[29][30][31] After O 2 plasma treatment, surface nanostructures and surface peroxo (O 2 2− ) species were formed, which favour the uniform and dense distribution of isolated strongly bonded Pt 2+ atoms. 32 Chae et al 33 also found that the discharge parameters (discharge power and time) of plasma effected the kinetics of the TiO 2 catalyst. Therefore, more and further research is necessary to study how the plasma discharge parameters (discharge power, time, and gas type) affect the catalyst resulting in the different performance of the catalyst.…”