Difference in peaks in EDS and XPS spectra
The two techniques are used for different purposes.
EDS - Is a &quot;bulk&quot; analysis technique.

Since the exciting electron is of high energy it penetrates relatively deeply into the sample.

The emitted x-rays have a characteristic energy which is unaffected by the chemical bonding. (There is some effect due to bonding of course, but the difference in energy is infinitesimally small and hence insignificant.)

High energy x-rays can escape through the sample to a &quot;great&quot; depth.


XPS is a surface analysis technique.

Exciting electrons of low energy and only penetrate the surface layers of the sample.

The bonding energies of the valence electrons are low in energy.

The emitted electrons have a low energy (few eV) and hence don't penetrate out of the sample except for the surface layers.