Platinum

Analysis of platinum by XPS is typically performed on the Pt 4f region. Platinum is very commonly found combined with alumina in heterogeneous catalysis, resulting in a very difficult deconvolution due to a significant overlap between the Pt 4f and Al 2p regions.

Pt 4f of mixed metal and PtO2 oxide may often appear to have similar peak areas for Pt 4f7/2 and Pt 4f5/2 due to a direct overlap between the Pt 4f5/2 of the Pt metal species and the Pt 4f7/2 of the PtO2 species (Figure 1). Take care to ensure peak areas are correctly locked (Pt 4f5/2 = Pt4f7/2 * 0.75). The doublet separation is 3.35 eV.

Figure 1: Pt metal/PtO2 mixtures(1)

A table of common binding energies may be found below:

Species Binding energy / eV Charge Ref. Ref.
Pt0 71.1 Ag 3d / 368.2 eV 2
PtO 72.4 Au 4f / 84 eV 3
PtO2 74.4 Au 4f / 84 eV 3
Table 1: Binding energies for common platinum species

References

[1] Durndell, L. J., et al. (2019). “Platinum catalysed aerobic selective oxidation of cinnamaldehyde to cinnamic acid.” Catalysis Today 333: 161-168. Read it online here.

[2] Colin, L., et al. (1996). “Adsorption and decomposition of hexamethyldisiloxane on platinum: an XPS, UPS and TDS study.” Applied Surface Science 99(3): 245-254. Read it online here

[3] Bancroft, G. M., et al. (1975). “ESCA study of sputtered platinum films.” Analytical Chemistry 47(3): 586-588. Read it online here.

Created: March 5, 2021