Maybe your system is more complex? Have you included a long Pt-O bond at around 2.5 A or just a short one at around 2A? Hard to help without seeing what the problem is.

Anatoly



Sent from my mobile phone, please forgive typos


-----Original message-----
From: Branko Zugic <Branko.Zugic@tufts.edu>
To: "ifeffit@millenia.cars.aps.anl.gov" <ifeffit@millenia.cars.aps.anl.gov>
Sent: Fri, Jul 27, 2012 15:28:37 GMT+00:00
Subject: [Ifeffit] Modeling Pt/C Catalyst Under WGS Conditions

Hello,

I am trying to interpret some in-situ Quick-EXAFS and EXAFS data that I took under water-gas shift conditions (CO + H2O diluted in He) on some Pt/C catalysts. I'm finding that the Pt-Pt and Pt-O fits using foil data, Pt-O standards, and quick 1st shell approximations for Pt-O aren't that great. After looking through the literature I came across some papers (i.e. http://pubs.acs.org/doi/abs/10.1021/jp983283e) that use the Ir-O and Ir-C interactions from Ir4(CO)12 to approximate Pt-O and Pt-C interactions. I then found some crystallographic tables for Ir4(CO)12 (below), but it's unclear to me whether I can use this to create an atoms inp file (and whether the data is for the structure I'm looking for or the referenced Ir(CO)3). So far I've had no luck.

Is this a reasonable approach to this problem? Is the information I have enough to do this? Any suggestions as to where I may be able to find the crystallographic data I am looking for?


Branko Zugic


--
PhD Candidate
Tufts University, Chemical and Biological Engineering
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