1 Department of Physics, Technical University of Denmark2 Experimental Surface and Nanomaterials Physics, Department of Physics, Technical University of Denmark3 Department of Chemical and Biochemical Engineering, Technical University of Denmark4 CHEC Research Centre, Department of Chemical and Biochemical Engineering, Technical University of Denmark5 Haldor Topsoe AS6 Haldor Topsoe AS
Ag/Al2O3 catalysts modified by Si, Ti, Mg and W were studied to obtain higher NOx SCR activity and potentially also higher SO2 resistance than the pure silver-based catalyst for automotive applications. Addition of Ti or Si to the alumina support leads to a better NOx removal at low temperature i.e. reduces the SCR onset temperature by about 10°C under the applied conditions. However, it does not increase the SO2 resistance. The catalysts and the supports have been characterized by BET, conventional and synchrotron XRD, X-ray absorption spectroscopy during temperature-programmed reduction (XAS-TPR) and temperature-programmed desorption of ammonia (NH3-TPD). The obtained results suggest a better silver dispersion and better regeneration capability in the case of Ti- and Si-modified Ag/Al2O3 catalysts.
Applied Catalysis B: Environmental, 2013, Vol 148-149, p. 62-69
Alumina; Catalyst regeneration; Doping (additives); Silicon; Silver; Sulfur dioxide; Temperature; Temperature programmed desorption; X ray absorption spectroscopy; Catalyst supports