AN XPS AND FTIR STUDY OF SO2 ADSORPTION ON SNO2 SURFACES

The adsorption of SO2, on SnO2, surfaces obtained from hydrolysis of S nCl4, and NH3 was studied by X-ray Photoelectron Spectroscopy. Tin dio xide surfaces were treated with SO2 at temperatures ranging from 300 t o 900 degrees C. For this temperature range, XPS shows that SO2 is ads orbed on till dioxide surfaces to form two sulphured species: SO32- fo r temperatures ranging from 300 to 500 degrees C and SO42-, for temper atures ranging from 300 to 900 degrees C. With regards to these two ch emical species, we were able to confirm their formation using a second analytical technique (FTIR). The formation of these species will be d iscussed in terms of a comparison between the results of the two techn iques, The role played by OH groups in these interactions is also disc ussed in this article.