A novel CuTi-containing catalyst derived from hydrotalcite-like compounds for selective catalytic reduction of NO with C3H6 under lean-burn conditions

Propene oxidation and NO reduction over MgCu–Al(Fe) mixed oxides derived from hydrotalcite-like compounds

“…Bridging nitrates (1631 cm −1 ) [1] and monodentate nitrates (1278 cm −1 ) [6] were detected over the catalyst. The observation of nitrates is attributed to the oxidation of NO by O 2 because the NO adsorbed on the catalyst surface cannot directly form nitrate species.…”

“…1(a) shows the XRD patterns of the as-synthesized hydrotalcite precursors where all samples presented the characteristic diffraction peaks of the hydrotalcite-like structure without any reflections of other possible phases, suggesting the complete incorporation of transition metals Fe and Cu into the crystalline structure. The formation of layered materials is evidenced by the sharp, symmetric, strong lines at low 2Â values and weaker, less symmetric lines at high 2Â values [1,13]. However, when aluminum is increasingly replaced by iron, the diffraction peaks are less intense, and a less crystallized hydrotalcite phase is obtained.…”

“…Diesel and other lean-burn gasoline vehicles are nowadays very popular, due to a better fuel efficiency and to lower CO 2 emissions in the atmosphere, compared to conventional stoichiometric engines [1,2]. However, the three ways catalyst which convert simultaneously hydrocarbons, NO x and CO, into N 2 , CO 2 and H 2 O are unable to reduce NO x in the presence of excess oxygen.…”

“…The compounds are found then processed according to the simplified equation: VOCs + NO x (+ O 2 ) → CO 2 + N 2 + H 2 O. Many researchers investigated the role of copper and iron species in the selective oxidation of propene and/or in the reduction of NO x [1,6,7]. However, it is known that copper oxides are very active in HC-SCR while little is known on the role of iron oxides in this process.…”

“…Among many applications, they are known to be powerful for hydrocarbons oxidation [9][10][11] and/or NO x reduction with hydrocarbons [1] or ammonia [12].…”