Temperature programmed desorption study on the mechanism of SO2 oxidation by activated carbon and activated carbon fibres

The mechanism of SO2 oxidation by O-2 on ACFs and ACFs has been studied ove r a wide variety of samples with different porosity and surface oxygen cont ent. Temperature programmed desorption experiments after SO, adsorption at room temperature and using gas mixtures with different compositions and in- situ FTIR experiments during the adsorption and the subsequent desorption, show that SO2 oxidation is inhibited by the oxygen complexes existing on th e carbon surface. The experiments also suggest that the SO2 oxidation occur s through the interaction of adsorbed SOL with OL in the gas phase by a mec hanism that follows an Eley-Rideal kinetic model. Desorption of SO, produce s carbon gasification and generates selectively CO-type oxygen complexes at the surface: CO2 gas is only formed through secondary reactions between SO , and CO. (C) 2001 Elsevier Science Ltd. All rights reserved.