La/Sr-based perovskites as soot oxidation catalysts for Gasoline Particulate Filters

Effect of Dopant Loading on the Structural and Catalytic Properties of Mn-Doped SrTiO3 Catalysts for Catalytic Soot Combustion

“…However, the sample doped by 8 wt % Mn showed a displacement to lower binding energies, with peaks at 640.9 and 641.8 eV. The earlier peaks are related to the existence of Mn 3+ and Mn 4+ on the surface of the catalyst while the latter could be associated with the formation of Mn 2+ and Mn 3+ on the surface of the Mn8 sample [13,26]. This behavior agrees well with the slight displacement to higher angles observed in Figure 1b for Mn1 sample, which can be associated with the differences in ionic radii among species.…”

“…The deconvolution analysis shows two well defined peaks in all samples located at 528.8 and 530.6 eV, which are respectively attributed to lattice oxygen (Olat) from the perovskite structure or surface segregated oxides and surface adsorbed oxygen (Oads), associated with defect oxides [27], carbonates or hydroxyl species, as well as weakly bonded oxygen adsorbed on the surface [13,26]. The Oads/Olat ratio shown in Table 2 demonstrates high Oads in the Mn1 sample, which can be attributed to the structural defects produced by the Mn 3+ /Mn 4+ ratio shown in Table 2 [1].…”

“…A new alternative is the use of transition metal oxides with perovskite structure which have been used as catalysts for soot and volatile organic compounds [7][8][9][10][11][12][13][14][15][16] or photocatalysts mainly related with the remotion of organic compounds [17,18]. Most perovskites, in particular SrTiO 3 , are characterized by high thermal stability, oxidative properties, and low cost, which make them good candidates for catalysts [7].…”

“…The sample with Mn showed the best catalytic activity during the soot oxidation reaction. They attributed this behavior to the Mn 4+ species, which can be locally reduced by transporting oxygen to the catalyst-soot interface [13].…”

“…Additionally, for SrTiO 3 , different metal can be incorporated as a metal dopant in the B site, making it a good candidate for soot oxidation [8,9]. On the other hand, LaMnO 3 has a similar structure and can also work as a catalyst in this reaction due the different Mn species in the B site [13]. For these reasons, and considering the different species of Mn, SrTiO 3 doped by Mn in Ti sites was tested as catalysts in soot combustion.…”