Investigation of the role of oxygen in NO reduction by C2H4 on the surface of stepped Pt(332)

Surface science studies of selective catalytic reduction of NO: Progress in the last ten years

“…The influence of oxygen on NO and C 2 H 4 reaction on Pt(3 3 2) has also been investigated in detail [149,150]. Several mechanisms have previously been proposed for describing the role of oxygen in the catalytic removal of NO with hydrocarbons, but so far, two mechanisms prove to be more capable of explaining the experimental results: (i) the presence of oxygen activates reactants (oxygen either oxidizes NO to NO x (x > 1) or oxidizes hydrocarbon to its oxygenate species that is then more readily oxidized by NO) and (ii) the presence of oxygen scavenges carbon species deposited on the working catalyst.…”

Metal–organic framework-derived CeO2–ZnO catalysts for C3H6-SCR of NO: an in situ DRIFTS study

“…1,2 Owing to the ground-breaking work of Iwamoto et al, hydrocarbon-selective catalytic reduction (HC-SCR) has become a promising technology for clearing NO x away from the automobile exhausts, taking into account the cost and gas components, as well as the hydrocarbons coexisting with NO in the exhaust streams. 3,4 Different kinds of hydrocarbons have been employed to improve the performance of HC-SCR, including propene, 5 methane, 6 ethanol, 7 ethylene, 8 and propane. 9 More importantly, catalysts are the core of this catalytic technology.…”

NO dissociation and N2 production in the presence of co-adsorbed S18O2 and D2 on Pt(332)

“…It is established that adsorbed S 18 O 2 molecules are dissociated when the surface temperature was increased to 200 K, giving rise to O atoms and SO species [21,22]. The resultant O atoms are the primary species that leads to the suppression of NO dissociation and subsequent N 2 at 200 K (oxygen-induced suppression in NO dissociation has been well established [41][42][43]). However, at higher surface temperatures, O atoms quickly react with S 18 O or S 18 O 2 to produce sulphoxy species (S 18 O x , x > 2) which further desorb as S 18 O 2 , resulting in many fewer O atoms remaining on platinum surface than that at 200 K. This is the reason that N 2 desorption gains intensity at 300 K and higher, even though the peak intensities are still much lower than that following only 0.8 L NO at 90 K.…”