The role of suprafacial oxygen in some perovskites for the catalytic combustion of soot

Fino, Debora; Russo, Nunzio; Saracco, Guido; Specchia, Vito

doi:10.1016/s0021-9517(03)00143-x

Cited by 260 publications

(161 citation statements)

References 30 publications

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“…The results obtained clarify the information compiled in Figure 2, On the other hand, the perovskite presents lower catalytic activity for soot oxidation under O 2 , but some activity is shown at high temperatures. Actually, it is known that oxygen vacancies can be created on this type of mixed oxide, mainly after proper doping with foreign cations [18][19][20] and re-filled with O 2 -gas phase, contributing to facilitate oxidation reactions.…”

Section: Resultsmentioning

confidence: 99%

Behavior of different soot combustion catalysts under NOx/O2. Importance of the catalyst–soot contact

Guillén-Hurtado

López-Suárez

Bueno‐López

et al. 2013

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Four different catalysts (Pt/Al 2 O 3 , Ce 0.8 Zr 0.2 O 2 , PrO 2-x and SrTiCuO 3 ) have been investigated in a laboratory scale to evaluate its potential as diesel soot catalysts under different experimental conditions, which simulate the situation found in a Continuously Regeneration Technology trap (dual-bed configuration of catalyst and soot) or a CatalystCoated Filter system, (single-bed configuration, both catalyst and soot particles mixed under loose-contact mode). Under dual-bed configuration, the catalysts' behaviours towards soot combustion are very similar, despite of the differences observed in the NO 2 production profiles. However, under single-bed configuration, there are important differences in the soot combustion activities and in the NO 2 slip profiles. The configurations chosen have an enormous impact on CO/(CO+CO 2 ) ratios of combustion products as well. The most active catalyst under NOx+O 2 is PrO 2-x combining high contribution of active oxygen-assisted soot combustion as well as high NO 2 production activity along the catalytic bed.

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Section: Resultsmentioning

confidence: 99%

Behavior of different soot combustion catalysts under NOx/O2. Importance of the catalyst–soot contact

Guillén-Hurtado

López-Suárez

Bueno‐López

et al. 2013

Reac Kinet Mech Cat

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“…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 (O lat ) from the perovskite structure or surface segregated oxides and surface adsorbed oxygen (O ads ), associated with defect oxides [27], carbonates or hydroxyl species, as well as weakly bonded oxygen adsorbed on the surface [13,26]. The O ads /O lat ratio shown in Table 2 demonstrates high O ads 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]. On the other hand, the Mn8 sample shows higher O lat , attributable to manganese oxides segregated on the surface of the catalyst, confirming a lower degree of distortion (Figure 1b) and the formation of Mn 2+ (Figure 3a).…”

Section: Resultsmentioning

confidence: 99%

“…Efforts to reduce of NO x and particulate matter in these emissions have been attracting more and more attention in the scientific community. In particular, fine soot particles have been associated with respiratory diseases and premature death by cancer [1]. In addition, the US-EPA has shown that soot particles are correlated with lung cancer in humans [2].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2018

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Soot particles have been associated with respiratory diseases and cancer. To decrease these emissions, perovskite-mixed oxides have been proposed due to their thermal stability and redox surface properties. In this work, SrTiO 3 doped with different amounts of Mn were synthesized by the hydrothermal method and tested for soot combustion. Results show that at low Mn content, structural distortion, and higher O ads /O lat ratio were observed which was attributed to the high content of Mn 3+ in Ti sites. On the other hand, increasing the Mn content led to surface segregation of manganese oxide. All synthesized catalysts showed mesopores in the range of 32-47 nm. In the catalytic combustion of soot, the samples synthesized in this work lowered the combustion temperature by more than 100 • C compared with the uncatalyzed reaction. The sample doped with 1 wt % of Mn showed the best catalytic activity. The activation energy of these samples was also calculated, and the order of decreasing activation energy is as follows: uncatalyzed > Mn0 > Mn8 > Mn4 > Mn1. The best catalytic activity for Mn1 was attributed to its physicochemical properties and the mobility of the oxygen from the bulk to the surface at temperatures higher than 500 • C.

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“…Devido às suas características intrínsecas, o cromito de lantânio torna-se adequado para aplicações como interconector em células a combustível de óxido sólido [23,[64][65][66][67], geradores magneto hidrodinâmicos (MHD) [68][69][70], catalisadores para queima de combustíveis [71][72][73], sensores de NO X em alta temperatura [74], resistências para fornos [75,76] e sensor potenciométrico de oxigênio [77]. Ainda na geração de energia, pode ser utilizado como ânodo para células de óxido sólido de temperatura intermediária (ITSOFC) [78][79][80][81][82][83].…”

Section: Aplicaçõesunclassified

“…As características do cromito de lantânio que atende a esta aplicação são: alta área de superfície específica e alta atividade catalítica [71][72][73].…”

Section: Aplicaçõesunclassified

Cromito de lantânio: material para interconectores de células a combustível de óxido sólido - uma revisão

2015

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INTRODUÇÃOMaterial sintético de grande importância tecnológica, o cromito de lantânio ainda se destaca como o principal material capaz de conduzir eletricidade em altas temperaturas suportando diferentes tipos de atmosferas frente a materiais como os aços inoxidáveis. Neste trabalho são revisadas as características, as propriedades, as possíveis aplicações e o comportamento durante o processamento do cromito de lantânio e de composições com diferentes tipos e teores de elementos dopantes. Estrutura cristalinaO LaCrO 3 apresenta uma estrutura cristalina do tipo perovskita, sendo considerado como pseudo-perovskita ou perovskita distorcida, por não ser perfeitamente cúbica como normalmente ocorre nas demais perovskitas da família ABO 3 [1]. Formando-se a partir de 650 °C, o LaCrO 3 apresenta célula unitária do tipo ortorrômbica (Pnma), ocorrendo uma transformação alotrópica para a estrutura romboédrica (R3c) durante o aquecimento no intervalo de temperatura entre 240 e 280 °C, tendo como consequência redução no volume do retículo, principalmente devido à redução de tamanho no octaedro CrO 6 . [2,3]. Trabalhos existentes [4] sugerem que esta estrutura permanece estável até a temperatura aproximada de 1800 °C, onde ocorre a transformação da estrutura romboédrica para a cúbica (Pm-3m) [5,6] ) é um material cerâmico sintético, que apresenta como principais características boa condutividade elétrica em altas temperaturas (> 800 °C), estabilidade química e física em atmosferas oxidantes e redutoras e, significativa atividade catalítica quando na forma de pós. Estas características o tornam atrativo para diversas aplicações de interesse tecnológico, como catalisadores, resistências para fornos de alta temperatura e geração de energia elétrica, sendo que nesse campo é potencialmente o material mais adequado para utilização como interconector em células a combustível de óxido sólido (Solid Oxide Fuel Cell -SOFC). As características intrínsecas, propriedades e técnicas de processamento do cromito de lantânio são consideradas neste trabalho por meio de uma revisão dos principais estudos relatados ao longo dos últimos 40 anos. Palavras-chave: cromito de lantânio, SOFC, revisão. AbstractThe lanthanum chromite (LaCrO 3 ) is a synthetic ceramic material, which has as main characteristics of good electrical conductivity at high temperatures (> 800 °C), physical and chemical stability in oxidizing and reducing atmospheres, and a significant catalytic activity when used as powder. These features make it attractive for various technological applications such as catalysts, resistance to high temperature furnaces and electric power generation, and this field is potentially the most appropriate material for use as interconnector in Solid Oxide Fuel Cells (SOFC). The intrinsic characteristics, properties and processing of lanthanum chromite are detailed in this paper through a review of major studies reported over the past 40 years.

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The role of suprafacial oxygen in some perovskites for the catalytic combustion of soot

Cited by 260 publications

References 30 publications

Behavior of different soot combustion catalysts under NOx/O2. Importance of the catalyst–soot contact

Behavior of different soot combustion catalysts under NOx/O2. Importance of the catalyst–soot contact

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

Cromito de lantânio: material para interconectores de células a combustível de óxido sólido - uma revisão

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