1st China-Japan Workshop on Environmental Catalysis and Eco-materials advances in environmental catalysis and eco-materials for the removal of pollutants from air and water - October 7-10, 2003, Beijing - Preface

The selective catalytic reduction (SCR) of NOx with propene over trace noble metals (Pt, Au and Pd)-modified Ag/Al2O3 catalysts in excess oxygen was studied. The activity test results show that 5% Ag-. 0.01% Pd/Al2O3 has a higher NOx conversion than Ag/Al2O3, especially at temperatures from 300 to 500 degreesC. However, the addition of Au and Pt into Ag/Al2O3 decreases the reaction activity. In situ diffuse reflectance infrared Fourier transform spectroscopy study suggests that the presence of Pd favors the formation of surface enolic species from the part oxidation of propene. The enolic species is very active to react with NO2 and NO3 to form -NCO species, which is the key reaction intermediate in the selective catalytic reduction of NOx