Hi Qiang:
It is exactly as you say. The number of metal-metal paths is small and not
well ordered. This washes out the scattering significantly. If the Pt is
in a more rigid well-ordered structure the second "shell" path is generally
more visible.
Carlo
On Thu, Feb 8, 2024 at 1:08 PM Qiang
Hi everyone,
I would like to have a discussion about the common EXAFS for single atom catalysts. It is usually observed that there is only one strong peak around 1.5A in EXAFS, and it is attributed to the nearest neighbors of O or N. Take an example of Pt1/CeO2 catalyst. Pt single atom is coordinated with a few oxygens, i.e., PtOx. These oxygens constitute the first shell of Pt. It is supposed that these O should also attach to the metal element of the support (Ce here). So there is also Pt-O-Ce structure. Why it doesnot have strong scattering peak in EXAFS? Is it that because the Pt-O-Ce formed is not ordered, or it is actually not a bond just some weak contact?
Thank you very much.
Qiang
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