Exploring the effect of using carbon black in the sol-gel synthesis of BaMnO3 and BaMn0.7Cu0.3O3 perovskite catalysts for CO oxidation

Torregrosa-Rivero, Verónica; Sánchez-Adsuar, María-Salvadora; Illán-Gómez, M.J.

doi:10.1016/j.cattod.2023.02.005

Cited by 9 publications

(16 citation statements)

References 54 publications

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“…Reducibility and redox properties of the catalysts were analyzed using temperatureprogrammed reduction with H2 (H2-TPR), which represents the consumption profiles shown in Figure 6a. For barium manganese-based samples, three different peaks are identified [36][37][38][64][65][66][67][68]: (i) a low-temperature peak, which appears between 400 • C and 500 • C, assigned to the reduction of Mn(IV) and Mn(III) to Mn(II); (ii) a low-intensity signal at temperatures between 700 • C and 800 • C, which corresponds to the reduction of oxygen species on the catalysts surface; and (iii) another low-intensity band at around 900 • C due to the reduction of bulk Mn(III) to Mn(II). In the B0.7M-E sample, a small amount of hydrogen consumption is observed below 400 • C, which confirms the presence of Mn(IV) in the catalyst [69].…”

Section: Redox Propertiesmentioning

confidence: 99%

“…Perovskite-based catalysts show a good oxygen storage capacity, since O 2 can be adsorbed and activated on the oxygen vacancies [30]. Therefore, BaMnO 3 solids have been used for GDI soot oxidation under the two different atmospheres indicated above [36], as well as for CO oxidation in simulated GDI exhaust engine conditions [37]. Additionally, we recently realized that the use of under-stoichiometric Ba x MnO 3 perovskites improves the performance of raw BaMnO 3 for CO oxidation, showing that Ba 0.7 MnO 3 formulation achieves the best results [38].…”

Section: Introductionmentioning

confidence: 99%

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Tailoring the Composition of BaxBO3 (B = Fe, Mn) Mixed Oxides as CO or Soot Oxidation Catalysts in Simulated GDI Engine Exhaust Conditions

et al. 2023

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Mixed oxides with perovskite-type structure (ABO3) are promising catalysts for atmospheric pollution control due to their interesting and tunable physicochemical properties. In this work, two series of BaxMnO3 and BaxFeO3 (x = 1 and 0.7) catalysts were synthesized using the sol–gel method adapted to aqueous medium. The samples were characterized by μ-XRF, XRD, FT-IR, XPS, H2-TPR, and O2-TPD. The catalytic activity for CO and GDI soot oxidation was determined by temperature-programmed reaction experiments (CO-TPR and soot-TPR, respectively). The results reveal that a decrease in the Ba content improved the catalytic performance of both catalysts, as B0.7M-E is more active than BM-E for CO oxidation, and B0.7F-E presents higher activity than BF for soot conversion in simulated GDI engine exhaust conditions. Manganese-based perovskites (BM-E and B0.7M-E) achieve better catalytic performance than iron-based perovskite (BF) for CO oxidation reaction due to the higher generation of actives sites.

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Section: Redox Propertiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Tailoring the Composition of BaxBO3 (B = Fe, Mn) Mixed Oxides as CO or Soot Oxidation Catalysts in Simulated GDI Engine Exhaust Conditions

et al. 2023

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“…All samples presented crystal phases corresponding to a perovskite structure: For the BMC sample, the BaMnO 3 polytype structure was the main crystal phase. This structure is a modification of the original hexagonal perovskite structure (shown for BaMnO 3 (BM) [ 27 ]), which is formed due to the partial substitution of Mn by Cu (in the B site of the perovskite lattice), which leads to a different rearrangement of the MO 6 octahedra [ 28 ]. For BMC-A, the addition of Ce, La or Mg provoked a partial reversion of the polytype structure to the hexagonal 2H-BaMnO 3 structure (PDF number: 026-0168, denoted by the ICDD, the International Centre of Diffraction Data), so the two crystal phases coexisted in the BMC-A samples.…”

Section: Resultsmentioning

confidence: 99%

“…For the BMC sample, the BaMnO 3 polytype structure was the main crystal phase. This structure is a modification of the original hexagonal perovskite structure (shown for BaMnO 3 (BM) [ 27 ]), which is formed due to the partial substitution of Mn by Cu (in the B site of the perovskite lattice), which leads to a different rearrangement of the MO 6 octahedra [ 28 ].…”

Section: Resultsmentioning

confidence: 99%

Improving the Catalytic Performance of BaMn0.7Cu0.3O3 Perovskite for CO Oxidation in Simulated Cars Exhaust Conditions by Partial Substitution of Ba

Ghezali,

Díaz Verde,

Illán Gómez

2024

Molecules

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The sol–gel method, adapted to aqueous media, was used for the synthesis of BaMn0.7Cu0.3O3 (BMC) and Ba0.9A0.1Mn0.7Cu0.3O3 (BMC-A, A = Ce, La or Mg) perovskite-type mixed oxides. These samples were fully characterized by ICP-OES, XRD, XPS, H2-TPR, BET, and O2–TPD and, subsequently, they were evaluated as catalysts for CO oxidation under different conditions simulating that found in cars exhaust. The characterization results show that after the partial replacement of Ba by A metal in BMC perovskite: (i) a fraction of the polytype structure was converted to the hexagonal BaMnO3 perovskite structure, (ii) A metal used as dopant was incorporated into the lattice of the perovskite, (iii) oxygen vacancies existed on the surface of samples, and iv) Mn(IV) and Mn(III) coexisted on the surface and in the bulk, with Mn(IV) being the main oxidation state on the surface. In the three reactant atmospheres used, all samples catalysed the CO to CO2 oxidation reaction, showing better performances after the addition of A metal and for reactant mixtures with low CO/O2 ratios. BMC-Ce was the most active catalyst because it combined the highest reducibility and oxygen mobility, the presence of copper and of oxygen vacancies on the surface, the contribution of the Ce(IV)/Ce(III) redox pair, and a high proportion of surface and bulk Mn(IV). At 200 °C and in the 0.1% CO + 10% O2 reactant gas mixture, the CO conversion using BMC-Ce was very similar to the achieved with a 1% Pt/Al2O3 (Pt-Al) reference catalyst.

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“…From a general point of view, the actual Ni content is very close to the nominal one, indicating that the method used for synthesis achieves the required amount of this metal. Moreover, the samples present a low BET surface area, as corresponds to mixed oxides with very low porosity development, such as perovskites [15,[19][20][21][22][23][24][25].…”

Section: Chemical and Morphological Propertiesmentioning

confidence: 99%

Ni-BaMnO3 Perovskite Catalysts for NOx-Assisted Soot Oxidation: Analyzing the Effect of the Nickel Addition Method

Montilla-Verdú,

Díaz-Verde,

Torregrosa-Rivero

et al. 2023

Catalysts

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In this study, we analyzed the role of a series of BaMn1−xNixO3 (x = 0, 0.2, and 0.4) mixed oxide catalysts, synthesized using the sol–gel method, in NOx-assisted diesel soot oxidation. ICP-OES, XRD, XPS, and H2-TPR techniques were used for characterization and Temperature-Programmed Reaction experiments (NOx-TPR and Soot-NOx-TPR), and isothermal reactions at 450 °C (for the most active sample) were carried out to determine the catalytic activity. All samples catalyzed NO and soot oxidation at temperatures below 400 °C, presenting nickel-containing catalysts with the highest soot conversion and selectivity to CO2. However, the nickel content did not significantly modify the catalytic performance, and in order to improve it, two catalysts (5 wt % in Ni) were synthesized via the hydrothermal method (BMN2H) and the impregnation of nickel on a BaMnO3 perovskite as support (M5). The two samples presented higher activity for NO and soot oxidation than BMN2E (obtained via the sol–gel method) as they presented more nickel on the surface (as determined via XPS). BMN2H was more active than M5 as it presented (i) more surface oxygen vacancies, which are active sites for oxidation reactions; (ii) improved redox properties; and (iii) a lower average crystal size for nickel (as NiO). As a consequence of these properties, BMN2H featured a high soot oxidation rate at 450 °C, which hindered the accumulation of soot during the reaction and, thus, the deactivation of the catalyst.

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Exploring the effect of using carbon black in the sol-gel synthesis of BaMnO3 and BaMn0.7Cu0.3O3 perovskite catalysts for CO oxidation

Cited by 9 publications

References 54 publications

Tailoring the Composition of BaxBO3 (B = Fe, Mn) Mixed Oxides as CO or Soot Oxidation Catalysts in Simulated GDI Engine Exhaust Conditions

Tailoring the Composition of BaxBO3 (B = Fe, Mn) Mixed Oxides as CO or Soot Oxidation Catalysts in Simulated GDI Engine Exhaust Conditions

Improving the Catalytic Performance of BaMn0.7Cu0.3O3 Perovskite for CO Oxidation in Simulated Cars Exhaust Conditions by Partial Substitution of Ba

Ni-BaMnO3 Perovskite Catalysts for NOx-Assisted Soot Oxidation: Analyzing the Effect of the Nickel Addition Method

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