Memory-dictated dynamics of single-atom Pt on CeO₂ for CO oxidation.

ABSTRACT: Single atoms of platinum group metals on CeO₂ represent a potential approach to lower precious metal requirements for automobile exhaust treatment catalysts. Here we show the dynamic evolution of two types of single-atom Pt (Pt₁) on CeO₂, i.e., adsorbed Pt₁ in Pt/CeO₂ and square planar Pt₁ in Pt_ATCeO₂, fabricated at 500 °C and by atom-trapping method at 800 °C, respectively. Adsorbed Pt₁ in Pt/CeO₂ is mobile with the in situ formation of few-atom Pt clusters during CO oxidation, contributing to high reactivity with near-zero reaction order in CO. In contrast, square planar Pt₁ in Pt_ATCeO₂ is strongly anchored to the support during CO oxidation leading to relatively low reactivity with a positive reaction order in CO. Reduction of both Pt/CeO₂ and Pt_ATCeO₂ in CO transforms Pt₁ to Pt nanoparticles. However, both catalysts retain the memory of their initial Pt₁ state after reoxidative treatments, which illustrates the importance of the initial single-atom structure in practical applications.

SUBMITTER: Zhang Z 

PROVIDER: S-EPMC10169862 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature