Reduction of NO x by H 2 on WO x -Promoted Pt/Al 2 O 3 /SiO 2 Catalysts Under O 2 -Rich Conditions

This work addresses the reduction of NO x by H 2 under O 2 -rich conditions using Al 2 O 3 /SiO 2 -supported Pt catalysts with different loads of WO x promotor. The samples were thoroughly characterised by N 2 physisorption, temperature-programmed desorption of CO, scanning electron microscopy, X-ray diffraction, laser raman spectroscopy, X-ray photoelectron spectroscopy and diffuse reflectance infrared fourier transform spectroscopy with probe molecule CO. The catalytic studies of the samples without WO x showed pronounced NO x conversion below 200 °C, whereas highest efficiency was related to small Pt particles. The introduction of WO x provided increasing deNO x activity as well as N 2 selectivity. This promoting effect was referred to an additional reaction path at the Pt-WO x /Al 2 O 3 /SiO 2 interface, whereas an electronic activation of Pt by strong metal support interaction was excluded. Graphic Abstract