Adsorption and interaction of H2S/SO2 on TiO2

Adsorption and interaction of H2S/SO2 on titania as well as on alumina for comparison has been studied by temperature programmed desorption (TPD), inf rared (IR) spectroscopy and temperature programmed electronic conductivity (TPEC) techniques. It was found that the adsorption of both H2S acid SO2 on TiO2 is much greater than on Al2O3. The electronic conductivity of TiO2 me asured by TPEC varies significantly as adsorption and desorption takes plac e on TiO2, showing a strong interaction between TiO2 and adsorbates. At tem perature above 200 degrees C, H2S or SO2 adsorbed on TiO2 can be converted into S, H2O and SO2 or SO3. While on the hydrogen treated TiO2, H2S is deco mposed into S and H-2, SO2 into S. The active sites on TiO2 surface cannot be so strongly adsorbed by SO2 that it is much more resistant to the sulfat ion reaction. Unlike TiO2, Al2O3 only provides surface adsorption sites, wh ich can be readily sulfated. The data obtained support one's understanding why TiO2 exhibits a better catalytic performance than that of Al2O3 as a Cl aus reaction catalyst. (C) 1999 Elsevier Science B.V. All rights reserved.