-
Since my last post yesterday, I found some leads and started to analyse my data. But then I started encountering more doubts, questions and confusion. Any help will be highly appreciated and will help me in speeding my research.
For analysis, I am matching the peak binding energy for each orbital for each element with the NIST Reference Database. During the analysis process I was confused how to guess in what form is the element/element’s present. I am not sure what I am doing is correct or not.
I am analysing XPS results of Pt impregnated on gamma alumina. I have 4 samples each subjected to different conditions. I am trying to figure out in what oxidation state/in what form the Pt will be present.
So I’ll give an example –
For Pt, I got a peak binding energy of 74.76 eV for the 4f7/2 orbital. When I searched this peak in the reference database, I got the following possible candidates with the following reference binding energies
a) PtO – 74.6 eV
b) PtO2 – 74.6 eV
c) Pt – 74.5 eV
This particular sample was fired in an engine and the temperatures were around 300 deg cel, and we don’t know exactly in what form the Pt will be present. How do I decipher in what state the Pt will present from the XPS data ?
Hi Omkar,
It would be good to see the data (even as just an image). One think is to be careful of your data, metallic Pt is 71.1 eV, but that can shift upwards with particle size for example, but nowhere near 74.5 eV.
PtO is ~ 74 eV, Pt(OH)2 is ~72.5 eV and PtO2 ~ 75 eV.
What is the biding energy of yout Al2p peak? What are you calibrating the data against? Carbon may not be the best here, so the Al2p, Al2s or O1s may be better here. Also recall that Pt4f overlap with the Al2p peak, so you have to be certian in what you’re looking at too!
Note that if is been fired in an engine, its liekly to have some oxide present unless you expect a very reducing environment
You must be logged in to reply to this topic.