The adsorption and thermal evolution of SO2 on a Pt(110) surface was studied by temperature programmed desorption, angle-resolved UV photoelectron spectroscopy and X-ray photoelectron spectroscopy. At 140 K two molecular SO2 species are observed that are attributed to adsorption on different adsorption sites. Upon heating to 340 K atomic S and molecular SO3 and SO4 are formed with the amount of the various products depending on the initial SO2 coverage. For high SO2 coverages these reactions are accompanied by molecular SO2 desorption. The SO3 species decomposes upon further heating to 500 K leading to SO2 desorption. SO4, which is only formed for high initial SO2 coverages, is stable up to this temperature but decomposes upon further heating to 650 K. In the same temperature range atomic sulphur and oxygen recombine to desorb as SO2.