Abstract: The elaboration of catalytic materials is related to abilities to effectively probe nano-scale structures. There is significant drawback to common XRD methods addressed to wellcrystallized materials, since catalyst components are often highly dispersed and present at low concentrations. The Pair Distribution Function (PDF) analysis based on operating with total scattering data is one of the techniques of choice for structural characterization of catalytic materials. Structural characterization of catalysts by the PDF analysis has attracted particular interest in the last years; the method has already proven itself a powerful technique for the study on highly dispersed, defect-rich and amorphous components of catalysts. The PDF describes local atomic structure of the material and provides structural information in the form of a radial distribution function of inter-atomic distances. In the talk, the PDFs calculated from synchrotron radiation data for different catalysts will be presented and types of structural information extracted from the PDFs will be discussed. The possibilities of the method to probe structure of supported nanoparticles in catalysts will be shown for some examples: 1) mono- and bimetallic (Pt, Rh)/γ-Al2O3 catalysts for hydrocarbon oxidation; 2) Ni/CeO2 catalyst for CO methanation 3) MoS2/Al2O3 hydrotreating catalysts. The data will illustrate that the PDF analysis is effective tool for study on structural organization of the supported catalysts and can be used to not only determine the nanoparticle structure but also assess particle shape, size of atomic ordering.

Cite: Pakharukova V.P. , Shmakov A.N.
Structural Analysis of Catalysts Using the Atomic Pair Distribution Function
International Conference "Synchrotron and Free electron laser Radiation: generation and application" 13-17 Jul 2020