BaFeO3−x Perovskite: An Efficient NOx Absorber with a High Sulfur Tolerance

Xian, Hui; Zhang, Xingwen; Li, Xingang; Li, Lingyun; Zou, Honghu; Meng, Ming; Li, Qian; Tan, Yisheng; Tsubaki, Noritatsu

doi:10.1021/jp100197c

Cited by 50 publications

(42 citation statements)

References 44 publications

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“…In the complex H 2 consumption profiles shown in Figure 6, three regions can be established [56,57,58]:At low temperature, between approximately 200 °C and 550 °C, a broad H 2 consumption signal is observed for all the catalyst that, according to literature, can be ascribed to different reduction processes: (i) the Cu(II) [34,38] reduction, (ii) the Fe(IV) and Fe(III) reduction to Fe(III) and Fe(II), as was observed for Fe 3 O 4 , and iii) the reduction of weakly chemisorbed oxygen upon surface oxygen vacancies of perovskite (α-oxygen) [34]. From around 550 °C to 700 °C, the H 2 consumption peaks correspond to both the reduction of Fe(III) to Fe(II) as detected for the reduction of Fe 3 O 4 to FeO and to the decomposition of surface oxygen species formed on oxygen vacancies (called α’-oxygen) [34], more strongly bonded to the perovskite than α-oxygen.At high temperatures (T > 700 °C), broad TCD signals assigned to the reduction of Fe(II) to Fe(0) (causing the consequent destruction of the perovskite structure) could be found [56,57,58]. Nevertheless, the XRD data for catalysts after H 2 -TPR (not shown) reveal that the perovskite structure is still present, thus, the reduction to Fe(0) is not taking place and, consequently, H 2 consumption is hardly observed at T > 700 °C.…”

Section: Resultsmentioning

confidence: 99%

BaFe1−xCuxO3 Perovskites as Active Phase for Diesel (DPF) and Gasoline Particle Filters (GPF)

et al. 2019

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BaFe1−xCuxO3 perovskites (x = 0, 0.1, 0.3 and 0.4) have been synthetized, characterized and tested for soot oxidation in both Diesel and Gasoline Direct Injection (GDI) exhaust conditions. The catalysts have been characterized by BET, ICP-OES, SEM-EDX, XRD, XPS, H2-TPR and O2-TPD and the results indicate the incorporation of copper in the perovskite lattice which leads to: (i) the deformation of the initial hexagonal perovskite structure for the catalyst with the lowest copper content (BFC1), (ii) the modification to cubic from hexagonal structure for the high copper content catalysts (BFC3 and BFC4), (iii) the creation of a minority segregated phase, BaOx-CuOx, in the highest copper content catalyst (BFC4), (iv) the rise in the quantity of oxygen vacancies/defects for the catalysts BFC3 and BFC4, and (v) the reduction in the amount of O2 released in the course of the O2-TPD tests as the copper content increases. The BaFe1−xCuxO3 perovskites catalyze both the NO2-assisted diesel soot oxidation (500 ppm NO, 5% O2) and, to a lesser extent, the soot oxidation under fuel cuts GDI operation conditions (1% O2). BFC0 is the most active catalysts as the activity seems to be mainly related with the amount of O2 evolved during an. O2-TPD, which decreases with copper content.

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Section: Resultsmentioning

confidence: 99%

BaFe1−xCuxO3 Perovskites as Active Phase for Diesel (DPF) and Gasoline Particle Filters (GPF)

et al. 2019

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“…Nevertheless, the BaSnO 3 formulation exhibited limited sulfur resistance. In this sense, a BaFeO 3 catalyst developed latter by Xian et al [87,103,104] showed a lower decrease of NSC after sulfating (about 11-12%). The incorporation of Ti improves sulfur resistance in a higher extent; activity decreased only 5.1% after SO 2 -pretreatment of a BaFe 1− xTi x O 3 catalyst (x = 0.1 or 0.2).…”

Section: No-to-no 2 Conversion (X No-to-no2 First Column) No X Stomentioning

confidence: 88%

“…Hence, diffusion of intermediate compounds from oxidation to adsorption sites was facilitated. Among all prepared catalysts, 30% La 0.7 Sr 0.3 CoO 3 /Al 2 O 3 sample achieved the most efficient use of perovskite phase due to the best balance between well-developed perovskite phase and NO oxidation and NO adsorption site distribution such as oxygen vacancies, structural La and Sr at the surface, and segregated SrCO 3 [86,87].…”

Section: Evolution Of α Desorbed Oxygen Species and No-to-no 2 Convermentioning

confidence: 99%

Perovskite-Based Formulations as Rival Platinum Catalysts for NO_x Removal in Diesel Exhaust Aftertreatment

Onrubia-Calvo¹,

Pereda‐Ayo²,

De‐La‐Torre³

et al. 2020

Perovskite Materials, Devices and Integration

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NO x removal is still a technological challenge in diesel engines. NO x storage and reduction (NSR), selective catalytic reduction (SCR), and combined NSR-SCR systems are the efficient approaches for diesel exhaust aftertreatment control. However, NSR and combined NSR-SCR technologies require high noble metal loadings, with low thermal stability and high cost. Recently, perovskites have gained special attention as an efficient alternative to substituting noble metals in heterogeneous catalysis. Up to date, few studies analyzed the application of perovskites in automobile catalytic converters. This chapter overviews recent research on development of novel perovskitebased catalysts as a component of single-NSR and hybrid NSR-SCR systems for NO x removal from diesel engine exhaust gases. Results in our laboratory are compared with similar work reported in the literature by other authors. Under realistic conditions, 0.5% Pd-30% La 0.5 Ba 0.5 CoO 3 /Al 2 O 3 catalyst achieves NO x-toN 2 conversion higher than 92% when is coupled with an SCR catalyst placed downstream. The results show promise for a considerably higher thermal stability and lower cost diesel exhaust treatment system.

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“…Thus, the BaSnO3 perovskite had the largest NOx storage capacity. In a series of consecutive studies BaCoO3 [80,81] and BaFeO3 [82][83][84] perovskites were also explored as alternatives with high NOx storage capacity and notable sulfur resistance. In these materials, the presence of BaCO3 as an impurity promoted the NOx adsorption capacity; however, this phase limited the regeneration capacity after SO2 poisoning.…”

Section: No X Adsorption Under Oxidizing Conditionsmentioning

confidence: 99%

Perovskite-Based Catalysts as Efficient, Durable, and Economical NOx Storage and Reduction Systems

2020

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Diesel engines operate under net oxidizing environment favoring lower fuel consumption and CO2 emissions than stoichiometric gasoline engines. However, NOx reduction and soot removal is still a technological challenge under such oxygen-rich conditions. Currently, NOx storage and reduction (NSR), also known as lean NOx trap (LNT), selective catalytic reduction (SCR), and hybrid NSR–SCR technologies are considered the most efficient control after treatment systems to remove NOx emission in diesel engines. However, NSR formulation requires high platinum group metals (PGMs) loads to achieve high NOx removal efficiency. This requisite increases the cost and reduces the hydrothermal stability of the catalyst. Recently, perovskites-type oxides (ABO3) have gained special attention as an efficient, economical, and thermally more stable alternative to PGM-based formulations in heterogeneous catalysis. Herein, this paper overviews the potential of perovskite-based formulations to reduce NOx from diesel engine exhaust gases throughout single-NSR and combined NSR–SCR technologies. In detail, the effect of the synthesis method and chemical composition over NO-to-NO2 conversion, NOx storage capacity, and NOx reduction efficiency is addressed. Furthermore, the NOx removal efficiency of optimal developed formulations is compared with respect to the current NSR model catalyst (1–1.5 wt % Pt–10–15 wt % BaO/Al2O3) in the absence and presence of SO2 and H2O in the feed stream, as occurs in the real automotive application. Main conclusions are finally summarized and future challenges highlighted.

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BaFeO_3−x Perovskite: An Efficient NO_x Absorber with a High Sulfur Tolerance

Cited by 50 publications

References 44 publications

BaFe1−xCuxO3 Perovskites as Active Phase for Diesel (DPF) and Gasoline Particle Filters (GPF)

BaFe1−xCuxO3 Perovskites as Active Phase for Diesel (DPF) and Gasoline Particle Filters (GPF)

Perovskite-Based Formulations as Rival Platinum Catalysts for NO_x Removal in Diesel Exhaust Aftertreatment

Perovskite-Based Catalysts as Efficient, Durable, and Economical NOx Storage and Reduction Systems

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BaFeO3−x Perovskite: An Efficient NOx Absorber with a High Sulfur Tolerance

Cited by 50 publications

References 44 publications

BaFe1−xCuxO3 Perovskites as Active Phase for Diesel (DPF) and Gasoline Particle Filters (GPF)

BaFe1−xCuxO3 Perovskites as Active Phase for Diesel (DPF) and Gasoline Particle Filters (GPF)

Perovskite-Based Formulations as Rival Platinum Catalysts for NOx Removal in Diesel Exhaust Aftertreatment

Perovskite-Based Catalysts as Efficient, Durable, and Economical NOx Storage and Reduction Systems

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BaFeO_3−x Perovskite: An Efficient NO_x Absorber with a High Sulfur Tolerance

Perovskite-Based Formulations as Rival Platinum Catalysts for NO_x Removal in Diesel Exhaust Aftertreatment