Copper doped BaMnO₃perovskite catalysts for NO oxidation and NO₂-assisted diesel soot removal

Abstract

BaMn0.7Cu0.3O3 is the most active catalyst for NO2 generation and soot oxidation. This behavior is a result of the enhancement of the redox properties of the catalyst due to the replacement of Mn(iii)/Mn(iv) by Cu(ii) in the perovskite structure.

BaFe1−xCuxO3 Perovskites as Soot Oxidation Catalysts for Gasoline Particulate Filters (GPF): A Preliminary Study

“…These results agree with that reported for coppersupported Ceria-zirconia catalysts for soot oxidation in GDI conditions [9]." "Copper content has a key role on the performance of the BaFe1-xCuxO3 catalyst for soot oxidation, which is in agreement with previous reports focused on diesel soot removal [13][14][15][16][17][27][28][29][30] and with that reported for copper-supported Ceria-zirconia catalysts for soot oxidation in GDSI conditions [9]." Answer to Reviewer #2 The authors synthesized composite oxides of Cu, Fe and Ba by a citrate sol-gel method, and investigated the properties and activities of the compounds obtained by their composition ratio.…”

“…The results of the Rietveld analysis confirm the structural modification detected by XRD. A sentence indicating this fact has been added to the manuscript: "This structural modification (which has been confirmed by the Rietveld analysis shown in Figure S1 in Supplementary information), was previously observed for other bariumbased perovskites [13,14,17] and also for Sn-doped BaFeO3 perovskites [18], seems to evidence the copper introduction into the perovskite lattice..", 3-Does the Cu segregation up to a certain load of Cu influence the catalytic activity? As it is discussed in the Catalytic activity section, the presence of copper species as segregated phase (BaOx-CuOx) seems to justify that BFC4 presents the highest activity as copper oxides are a well-known catalysts for oxidation reaction.…”

“…Among the different catalysts proposed for soot oxidation, mixed oxides with perovskite structure (general formula ABO3) are very attractive as their properties depend on the nature of A and B cations and, consequently, its composition can be fitted [10] to the requirements of the oxidation reaction. In fact, perovskites are a promising alternative as soot oxidation catalysts in DPF conditions [11][12][13][14][15][16]. In previous reports [13,14], the beneficial effect of copper partially incorporated into the structure of BaTiO3 and BaMnO3 perovskites for NO2-assisted diesel soot oxidation has been shown.…”

“…In fact, perovskites are a promising alternative as soot oxidation catalysts in DPF conditions [11][12][13][14][15][16]. In previous reports [13,14], the beneficial effect of copper partially incorporated into the structure of BaTiO3 and BaMnO3 perovskites for NO2-assisted diesel soot oxidation has been shown. Recently, Hernández et al [7,8] have reported that iron-based perovskites are interesting as soot oxidation catalysts in GDI exhaust conditions (1% O2).…”

BaTi0.8B0.2O3 (B = Mn, Fe, Co, Cu) LNT Catalysts: Effect of Partial Ti Substitution on NOx Storage Capacity

“…This result seems to be explained considering that BTCuO_2 catalyst presents a positive imbalance larger than the other catalysts due to the highest difference between the oxidation state of Ti 4+ and the Cu +2 (Fe and Mn appear mainly as Fe(II) and Mn(III) but Fe(III) and Mn(IV) have been also identified by XPS). Additionally, surface oxygen vacancies are also created because Ti +4 cannot achieve a higher oxidation state as other B cations (as Mn or Fe in BaMn [20,21]) do. Finally, it is remarkable that BTCuO_2 catalyst preserves the original tetragonal structure (shown by XRD and Raman results), but with a high degree of distortion, which causes the presence of a larger amount of oxygen vacancies.…”