XPS and SSIMS studies of Pd/SnOx system: reduction and oxidation in hydrogen containing air

In this work the study of a redox process on Pd/SnOx system by means of X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectrometry (SSIMS) is presented. SnOx substrates were prepared by spray pyrolysis onto Si(1 1 1). Palladium ultra-thin films were evaporated in UHV chamber and then stabilised in air at 720 K for 2 h. Results obtained after thermal treatment in 1% H2 containing air and in pure air showed the reversible change in palladium chemical state.