Síntese e caracterização de perovskitas LaNi(1-x)Co xO3 como precursores de catalisadores para a conversão do metano a gás de síntese pela reforma com CO2

Lima, Sania M. de; Assaf, José Mansur

doi:10.1590/s0100-40422007000200011

Cited by 10 publications

(7 citation statements)

References 21 publications

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“…A), and the second peak corresponded to the reduction of Ni 2+ to Ni 0 , with formation of metallic nickel (Eq. B) [15,25]. In addition, a third peak at 670 °C was observed for a possible formation of nonstoichiometric nickel aluminate (NiO-α-Al 2 O 3 ) [26], due to an interaction between NiO of the segregated phase with the support alumina (Eq.…”

Section: Wavenumber (Cm -1 )mentioning

confidence: 99%

“…In general, the perovskite properties are influenced by the synthesis method, calcination conditions (temperature, time and atmosphere) and substitutions at sites A and/or B. There are now several methods of obtaining ceramics oxides with perovskite type structure, such as the conventional powder technology, the Pechini method, the chelating precursor method, the proteic sol-gel method and the combustion synthesis process, among others [13][14][15]. Some researchers have used synthetic routes similar to the polymer precursor method in which gelatin replaces ethylene glycol as a polymerization agent to obtain nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

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Nickel-based perovskite catalysts: synthesis and catalytic tests in the production of syngas

et al. 2018

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La 1-x Sr x NiO 3 (x= 0.0, 0.3 or 0.7) perovskite-type oxides were synthesized using the modified proteic gel method and using collagen as an organic precursor. Catalysts of La 1-x Sr x NiO 3 /Al 2 O 3 were obtained using the wet impregnation method. The synthesized catalysts were characterized by X-ray diffraction, surface area and temperature-programmed reduction. The catalysts were evaluated in the partial oxidation reaction of methane, and the levels of selectivity to CO, CO 2 , H 2 and H 2 O were determined. Among the catalysts studied, the catalyst LaNiO 3 /Al 2 O 3 had the highest methane conversion level (78%) and higher H 2 selectivity (55%). Keywords: La 1-x Sr x NiO 3 , perovskite-type oxides, modified proteic gel method, partial oxidation of methane. Resumo Perovskitas do tipo

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Section: Wavenumber (Cm -1 )mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nickel-based perovskite catalysts: synthesis and catalytic tests in the production of syngas

et al. 2018

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“…Na catálise, diversos trabalhos têm confirmado a multifuncionalidade das perovskitas. Desse modo as perovskitas têm sido aplicadas na oxidação total do etanol [5], na conversão do metano a gás de síntese pela reforma com CO2 [6] e na redução de NO ou hidrogênio para produzir CO2 e N2 [7].…”

Section: Introductionunclassified

Estudo de obtenção da membrana cerâmica densa BaCeO3

et al. 2019

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RESUMO Nos últimos anos, pós cerâmicos à base de óxidos de estrutura do tipo perovskita ganharam atenção considerável devido às suas aplicações tecnológicas na área de membranas permeáveis de oxigênio. O óxido misto BaCeO3 apesenta-se como um material amplamente estudado em uma grande diversidade de aplicações, seja como materiais eletrolíticos em células a combustível, ou mesmo como catalisadores nas reações de catálise. Dessa forma, o presente trabalho teve como objetivo sintetizar a fase BaCeO3, pelo método de coprecipitação em meio oxalato, verificando o efeito da sinterização com diferentes aglutinantes na estabilidade térmica e densificação da membrana. A técnica de coprecipitação em meio oxalato mostrouse eficaz na obtenção da perovskita BaCeO3. As amostras obtidas durante as sínteses foram caracterizadas por difração de raios-x, observando-se a formação da fase ortorrômbica da perovskita BaCeO3. Para determinar o tamanho médio de cristalito foi utilizada a equação de Scherrer e de Williamson Hall, chegando-se a um valor próximo a de 107 nm. Conforme a literatura [1,2] e diante dos resultados apresentados definiu-se como condições favoráveis para formação de material com o menor tamanho de cristalito e maior pureza da fase formada, a amostra de pH 13 e de temperatura de calcinação de 1000 ºC. Através da microscopia eletrônica de varredura (MEV) pode-se observar a formação de cristais homogêneos. Por fim, foi possível observar que a sinterização na presença dos aglutinantes parafina e álcool polivinílico a 1300 ºC com patamar de 5 h, permitiu a obtenção de pastilhas densas com bons níveis de retração, possuindo estabilidade térmica ideal para serem utilizadas como membranas permeáveis de oxigênio e como eletrólito de células a combustível.

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“…This fact is attributed to the capacity of this simple structure to accommodate a wide variety of ions with different valences and it can be easily synthesized due to its chemical structure flexibility [10,11], indicating the importance of this type of perovskite oxide. However, only a small fraction of materials presenting perovskite structure has been explored in the catalysis field at low temperature [12][13][14], although a catalyst is actually used in the majority of the chemical and petrochemical industrial processes. Some perovskites with different compositions were tested as catalysts by Doggali et al [15] and Seyfi et al [16] on carbon monoxide oxidation.…”

Section: Introductionmentioning

confidence: 99%

LaNi0.3Co0.7O3-δ and SrFe0.2Co0.8O3-δ Ceramic Materials: Structural and Catalytic Reactivity under CO Stream

et al. 2014

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Abstract:In this study, we presented the synthesis of LaNi 0.3 Co 0.7 O 3−δ (LNCO) and SrCo 0.8 Fe 0.2 O 3−δ (SFCO) perovskites and their catalytic reactivity under CO gas flow. The synthesis method is based on the complexation method combining ethylenediaminetetraacetic acid (EDTA)-citrate. The as-prepared materials were characterized using X-ray diffraction/Rietveld refinement and electron microscopy. The diffractograms and Rietveld refinement showed that the EDTA-citrate method allows us to obtain monophasic powders with submicronic size. The structural analyses revealed different morphologies linked to the crystallinity of LNCO and SFCO, and to the mean crystallite size. The catalytic performances of LNCO and SFCO were studied in situ by Fourier Transform InfraRed spectrometer as a function of time and temperature. The catalytic process gave rise to total oxidation with carbon dioxide and water production. LNCO and SFCO exhibit the same profile for catalytic activity with a conversion rate of twice as high for LNCO. Below 150 °C, the kinetic conversion is slow, but beyond this temperature they reach rapidly the complete transformation at 250 °C and 275 °C for LNCO and SFCO, respectively. OPEN ACCESSCatalysts 2014, 4 78

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Síntese e caracterização de perovskitas LaNi(1-x)Co xO3 como precursores de catalisadores para a conversão do metano a gás de síntese pela reforma com CO2

Cited by 10 publications

References 21 publications

Nickel-based perovskite catalysts: synthesis and catalytic tests in the production of syngas

Nickel-based perovskite catalysts: synthesis and catalytic tests in the production of syngas

Estudo de obtenção da membrana cerâmica densa BaCeO3

LaNi0.3Co0.7O3-δ and SrFe0.2Co0.8O3-δ Ceramic Materials: Structural and Catalytic Reactivity under CO Stream

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