DISSOCIATIVE ADSORPTION OF SULFUR-DIOXIDE ON GAMMA-ALUMINA INVESTIGATED BY TPD AND MASS-SPECTROMETRY

Prior studies on the adsorption of SO2 on gamma-alumina are not partic ularly revealing about the SO2-alumina surface interactions. Chemisorb ed SO2 on alumina was examined using a TPD-MS approach. The use of (SO 2)-O-18 clearly demonstrated that both molecular and dissociated forms of SO2 chemisorb on the surface of gamma-alumina. The most likely mod e of adsorption apparently involves interaction between oxygen atoms i n the gaseous molecule and oxygen vacancies on the surface of alumina. The experiments also reveal the freedom of surface protons to form hy droxyl groups on the alumina surface.