Fluorescence-detected XAS with sub-second time resolution reveals new details about the redox activity of Pt/CeO₂ catalyst.

ABSTRACT: A setup for fluorescence-detected X-ray absorption spectroscopy (XAS) with sub-second time resolution has been developed. This technique allows chemical speciation of low-concentrated materials embedded in highly absorbing matrices, which cannot be studied using transmission XAS. Using this setup, the reactivity of 1.5 wt% Pt/CeO₂ catalyst was studied with 100 ms resolution during periodic cycling in CO- and oxygen-containing atmospheres in a plug-flow reactor. Measurements were performed at the Pt L₃- and Ce L₃-edges. The reactivity of platinum and cerium demonstrated a strong correlation. The oxidation of the catalyst starts on the ceria support helping the oxidation of platinum nanoparticles. The new time-resolved XAS setup can be applied to various syst

SUBMITTER: Guda AA 

PROVIDER: S-EPMC6038606 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature