Adsorption and interaction of H2S/SO2 on TiO2

Abstract Adsorption and interaction of H 2 S/SO 2 on titania as well as on alumina for comparison has been studied by temperature programmed desorption (TPD), infrared (IR) spectroscopy and temperature programmed electronic conductivity (TPEC) techniques. It was found that the adsorption of both H 2 S and SO 2 on TiO 2 is much greater than on Al 2 O 3 . The electronic conductivity of TiO 2 measured by TPEC varies significantly as adsorption and desorption takes place on TiO 2 , showing a strong interaction between TiO 2 and adsorbates. At temperature above 200°C, H 2 S or SO 2 adsorbed on TiO 2 can be converted into S, H 2 O and SO 2 or SO 3 . While on the hydrogen treated TiO 2 , H 2 S is decomposed into S and H 2 , SO 2 into S. The active sites on TiO 2 surface cannot be so strongly adsorbed by SO 2 that it is much more resistant to the sulfation reaction. Unlike TiO 2 , Al 2 O 3 only provides surface adsorption sites, which can be readily sulfated. The data obtained support one's understanding why TiO 2 exhibits a better catalytic performance than that of Al 2 O 3 as a Claus reaction catalyst.