Determination of adsorbed species in the surface hydrolysis of SOF 2 on activated alumina

The nature of the species adsorbed in the hydrolysis of SOF₂ on activated alumina has been investigated using spectroscopic XPS and FTIR techniques. XPS technique proved to be a convenient tool for determining the amount of adsorbed species, especially when they are strongly bonded. The amount of fluorine detected by XPS confirmed its strong interaction with alumina, although the formation of an alumina-fluorine complex was not observed. With regards to the adsorbed sulfur complexes, the S 2p XPS binding energy (BE) associated with the features of the FTIR spectra (around 1000-1200 cm^-1) suggests the presence of both chemisorbed SO₃ (sulfite) and SO₂ F (fluorosulfite) species on alumina. Lastly, the decreasing amount of oxygenated species detected by XPS suggests that the presence of adsorbed fluorine has a significant impact on the retention capability of alumina toward moisture