Re: [Ifeffit] weak scattering from second-nearest neighbors for single atom catalysts

[Anatoly Frenkel]

Hi Qiang,

There are many papers analyzing Pt SACs on ceria and many of them are able
to provide good evidence of Pt-O-Ce coordination. See for example Fig. 5d
in this paper and the discussion of the model and fit results.

M. Kottwitz, Y. Li, R. M. Palomino, Z. Liu, Q. Wu, G. Wang, J. Huang, J.
Timoshenko, S. D. Senanayake, M. Balasubramanian, D. Lu, R. G. Nuzzo, A. I.
Frenkel
*Local structure and electronic state of atomically dispersed Pt on
nanosized CeO2 support*
ACS Catalysis *9*, 8738-8748 (2019)


Regards,
Anatoly

On sabbatical leave at PSI, Switzerland.

---
Anatoly I. Frenkel
Professor
Department of Materials Science and Chemical Engineering (primary
appointment)
Department of Chemistry (affiliate appointment)
* Stony Brook University *
Stony Brook, NY 11794
Email:  anatoly.fren...@stonybrook.edu

http://you.stonybrook.edu/frenkel
Co-Director and Spokesperson, Synchrotron Catalysis Consortium (SCC) at BNL
http://you.stonybrook.edu/scc2

Joint Appointment:
Senior Chemist
Chemistry Division, *Brookhaven National Laboratory*
Upton, NY 11973
Email: fren...@bnl.gov
https://www.bnl.gov/staff/frenkel
---


On Thu, Feb 8, 2024 at 2:08 PM Qiang  wrote:

> 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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[Ifeffit] weak scattering from second-nearest neighbors for single atom catalysts

[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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