The Journal of Materials Chemistry A has published a work of the Surface Physics and Nanomaterials groups and three cooperating Italian institutions, Ultimate dispersion of metallic and ionic platinum on ceria by Andrii Tovt, Luigi Bagolini, Filip Dvořák, Nguyen-Dung Tran, Mykhailo Vorokhta, Klára Beranová, Viktor Johánek, Matteo Farnesi Camellone, Tomáš Skála, Iva Matolínová, Josef Mysliveček, Stefano Fabris, and Vladimír Matolín.
The authors investigated experimentally and theoretically how the level of platinum dispersion in Pt/ceria catalysts depends on two key factors, the amount of deposited platinum and the oxidation state of the ceria support. One important finding is that oxidized ceria stabilizes single Pt2+ ions, particularly at monoatomic step edges of the CeO2(111) surface. Even more remarkable is the finding that platinum clusters (nanoparticles) on the ceria surface can be redispersed into single Pt2+ ions by annealing the catalyst in an oxygen atmosphere.
Single Pt2+ ions represent the ultimate dispersion, so called single-atom catalyst, providing the most efficient utilization of the precious metal—every single atom is exposed to the reactants and exerts its catalytic properties.
Image reproduced by permission of Josef Mysliveček and The Royal Society of Chemistry from J. Mater. Chem. A, 2019, 7, 13019-13028, https://doi.org/10.1039/C9TA00823C.