Ultimate dispersion of metallic and ionic platinum on ceria

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 7; no. 21; pp. 1319 - 1328
• Main Authors: Tovt, Andrii, Bagolini, Luigi, Dvo ák, Filip, Tran, Nguyen-Dung, Vorokhta, Mykhailo, Beranová, Klára, Johánek, Viktor, Farnesi Camellone, Matteo, Skála, Tomáš, Matolínová, Iva, Myslive ek, Josef, Fabris, Stefano, Matolín, Vladimír
• Format: Journal Article
• Language: English
• Published: 2019
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c9ta00823c

Ceria represents a technologically indispensable reducible catalyst support. Besides the general impact on the surface chemistry, the oxygen content of the ceria surface directly influences the dispersion of ceria-supported metal nanoparticles, and the properties of ceria-supported metal catalysts. We investigate the role of oxygen atoms on a CeO 2 (111) surface in supporting Pt as smallest metallic Pt clusters or, concurrently, as monodispersed Pt 2+ ions. We demonstrate that the necessary condition for the formation of Pt 2+ ions is the availability of lattice O or excess O atoms at surface step edges. Although Pt 2+ ions can exist on partially reduced surfaces, excess O atoms are required to maximize the capacity of the surface to accommodate Pt 2+ and to trigger the redispersion of metallic Pt clusters. Our study provides atomic-level understanding and control of the highest dispersions of Pt on the ceria surface for advancing the state-of-the-art Pt/ceria catalysts that are presently identified at the verge of single-atom Pt dispersion. Smallest metallic (blue) and ionic (grey) Pt objects on ceria are shaped and controlled by surface oxygen content.