SrFeO3-δPerovskite Oxides:  Chemical Features and Performance for Methane Combustion

Falcón, Horacio; Barbero, J. A.; Alonso, J. A.; Martínez-Lope, § and M. J.; Fierro, J.L.G.

doi:10.1021/cm011292l

Cited by 182 publications

(146 citation statements)

References 31 publications

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“…Observou-se a presença da fase correspondente à estrutura perovskita. O óxido não substituído LaNiO 3 pertence ao sistema romboédrico, grupo espacial R3c (N167), com parâmetros hexagonais a = 0,54573 nm e c = 1,31601 nm [12]. Os sólidos parcialmente substituídos (Amostras LaNi 0,7 Cu 0,3 O 3 e LaNi 0,5 Cu 0,5 O 3 ) apresentaram o padrão com a mesma simetria do composto não substituído.…”

Section: Resultsunclassified

“…O uso desses catalisadores deverá permitir a produção de hidrogênio com um nível de pureza superior àquele obtido no processo convencional de reforma, uma vez que os sólidos com a estrutura perovskita constituem um sistema alternativo atrativo para catalisar a reação de deslocamento de monóxido de carbono com vapor d`água [10][11][12]. Estes sólidos possuem a fórmula ABO 3 , em que A é o cátion de tamanho maior, responsável pela resistência térmica do catalisador, enquanto B é o cátion associado com a atividade catalítica.…”

Section: Introductionunclassified

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Síntese e caracterização de perovskitas do tipo LaNi1-xCu xO3 para a purificação de hidrogênio para PaCOS

Moura¹,

Silva²,

Rangel³

et al. 2010

Matéria (Rio J.)

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RESUMONeste trabalho, foram estudados sólidos do tipo LaNi1-xCuxO3 (x = 0,0; 0,3 e 0,5), com estrutura perovskita, visando a desenvolver catalisadores destinados à produção de hidrogênio de alta pureza na reforma interna de células a combustível de óxido sólido (SOFC). Observou-se que as condições experimentais usadas na preparação favoreceram a incorporação quantitativa dos cátions ao precursor e a formação dos sólidos com estrutura perovskita. Esses materiais mostraram diferentes propriedades redutoras e a presença do cobre favoreceu a estabilidade da estrutura perovskita. As propriedades catalíticas das amostras obtidas foram avaliadas na reação de deslocamento de monóxido de carbono com vapor d`água (WGSR, water gas shift reaction), uma etapa importante de purificação do hidrogênio, no processo de reforma de hidrocarbonetos. Os resultados mostraram que os catalisadores são promissores para esta reação, apresentando atividade muito superior à de um catalisador comercial de óxido de ferro contendo cromo e cobre; isto foi atribuído à tendência das amostras em favorecer o mecanismo adsortivo, provavelmente decorrente de uma alta mobilidade dos oxigênios da rede cristalina. O valor mais elevado de atividade catalítica foi apresentado pela Amostra LaNi0,5Cu0,5O3, considerada o catalisador de melhor desempenho.Palavras-chave: Perovskita, produção de hidrogênio, conversão de CO, níquel e cobre. ABSTRACTLaNi 1-x Cu x O 3 (x = 0.0, 0.3 and 0.5) type solids with perovskite structure were studied in this work aiming to develop catalysts for the production of high pure hydrogen in the internal reforming of solid oxide fuel cells (SOFC). It was observed that the experimental conditions used for preparing the samples favored the quantitative incorporation of cations in the precursor and the formation of solids with perovskite structure. These materials showed different reducing properties and the copper presence favored the stability of the perovskite structure. The catalytic properties of the samples were evaluated in water gas shift reaction (WGSR), an important step for purifying hydrogen in the process of hydrocarbons reforming. The results showed that the catalysts are promising for the reaction, showing much higher activities than a iron oxidebased commercial catalyst containing chromium and copper; This was assigned to the tendency of the samples in favoring the adsorptive mechanism, probably due to a high mobility of oxygen in the crystalline lattice. The highest value of catalytic activity was shown by the LaNi 0.5 Cu 0.5 O 3 sample, the catalyst with the best performance.

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Section: Resultsunclassified

Section: Introductionunclassified

Síntese e caracterização de perovskitas do tipo LaNi1-xCu xO3 para a purificação de hidrogênio para PaCOS

Moura¹,

Silva²,

Rangel³

et al. 2010

Matéria (Rio J.)

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“…Furthermore, the surface of the oxygen electrodes is not static, the corresponding structure and surface chemistry (i.e., cation concentration and oxygen nonstoichiometry) are driven dynamically by the surrounding chemical environment, temperature, and oxygen partial pressure (Po 2 ). 14,15,16,17,18,19,20,21 For example, on the surface of La 1-x Sr x MnO 3 , a widely studied perovskite-type oxide anode/cathode, the concentration of Sr-dopant cation was shown to increase with decreasing Po 2 14 and increasing temperature (greater than 500qC), 15 and the electron transfer ease (measured by tunneling conductance on the surface) was found to decrease with increasing Sr. 15 On another well-studied perovskite, SrTiO 3 , the surface was drastically altered for both oxidizing (800 to 1000qC, 200 Torr O 2 ) and reducing conditions (1000qC, 10 -8 Torr O 2 ) in comparison with the original stoichiometric surfaces. 22 While oxidizing conditions induced the formation of a Sr-rich Ruddlesden-Popper phase on the surface of SrTiO 3 , reducing conditions caused the formation of Ti-rich phases such as titanium oxide and Ti 2 O.…”

Section: Introductionmentioning

confidence: 99%

Summary Report on Solid-oxide Electrolysis Cell Testing and Development

O’Brien¹,

Zhang²,

O’Brien³

et al. 2012

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EXECUTIVE SUMMARYIdaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cells (SOECs) for large-scale hydrogen production from steam over a temperature range of 800 to 900°C. From 2003 to 2009, this work was sponsored by the United States Department of Energy Nuclear Hydrogen Initiative, under the Office of Nuclear Energy. Starting in 2010, the high-temperature electrolysis (HTE) research program has been sponsored by the INL Next Generation Nuclear Plant Project. This report provides a summaryof program activities performed in Fiscal Year (FY) 2011 and the first quarter of FY-12, with a focus on small-scale testing and cell development activities. HTE research priorities during this period have included the development and testing of SOEC and stack designs that exhibit high-efficiency initial performance and low, long-term degradation rates. MSRI worked closely with INL as a subcontractor responsible for development and testing of advanced electrode-supported solid-oxide cells and stacks, optimized for operation in the electrolysis mode. MSRI also provided several stacks and single cells to INL for independent testing and characterization. Testing at both locations included several long-term (more than 1000 hours) stack durability tests. Test results were very favorable, with excellent initial performance and low degradation rates (less than 3%/khr). Based on the test results, and the development of an excellent working relationship, MSRI was selected as the supplier for cells and stacks for two major FY-12 program objectives: (1) demonstration of HTE at the 4-kW scale for 1000 hours using advanced technology cell and stack hardware, and (2) demonstration of pressurized operation of an HTE stack at a pressure of 1.5 MPa or higher.VPS is a major developer of solid-oxide fuel cells and a member of the United States Department of Energy Solid State Energy Conversion Alliance. INL contracted with VPS in FY-10 for electrolysis testing activities performed at their research facility in Calgary, Alberta, Canada. Some of the test activities, including a stack test that ran for more than 4500 hours, extended into FY-11 and are therefore included in this report. VPS also examined the effects of constant current versus constant voltage operation. HTE test results performed at VPS were excellent. The stacks exhibited good initial performance and very low degradation rates (less than 1.5%/khr).Ceramatec, Incorporated, continued to be an important contributor to the INL HTE Program during FY-11. Primary research objectives for FY-11 included continued refinement of the air-electrode material set to address various degradation mechanisms, development of an air-electrode-supported cell with a thin electrolyte, and development of a new double-doped electrolyte. Ceramatec also delivered several SOEC stacks to INL for testing and also performed their own in-house testing. One of the stacks was operated at INL for more than 2000 hours, with very stable long-term performance, even showing i...

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“…The crystalline structure and the partial substitution of some of their cations by other elements with a different oxidation state confer to these compounds very interesting properties [2] and [3] and an enhanced activity for the oxidation of (unburned) hydrocarbons [4], [5] and [6], soot particles [7] and [8] or volatile organic compounds (VOCs) [9], [10] and [11]. The oxidation of carbon monoxide has been also extensively studied not only as a model gas to prove the adsorption sites over the perovskites [12], [13] and [14], but also because of its environmental impact as one of the most hazardous pollutants produced by mobile sources [15] and [16].…”

Section: Introductionmentioning

confidence: 99%

Near-ambient X-ray photoemission spectroscopy and kinetic approach to the mechanism of carbon monoxide oxidation over lanthanum substituted cobaltites

Hueso

Martínez-Martínez

Caballero

et al. 2009

Catalysis Communications

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We have studied the oxidation of carbon monoxide over a lanthanum substituted perovskite (La 0.5 Sr 0.5 CoO 3−d ) catalyst prepared by spray pyrolysis. Under the assumption of a first-order kinetics mechanism for CO, it has been found that the activation energy barrier of the reaction changes from 80 to 40 kJ mol −1 at a threshold temperature of ca. 320 °C. In situ XPS nearambient pressure ( 0.2 torr) shows that the gas phase oxygen concentration over the sample decreases sharply at ca. 300 °C. These two observations suggest that the oxidation of CO undergoes a change of mechanism at temperatures higher than 300 °C.

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SrFeO₃_-_δPerovskite Oxides: Chemical Features and Performance for Methane Combustion

Cited by 182 publications

References 31 publications

Síntese e caracterização de perovskitas do tipo LaNi1-xCu xO3 para a purificação de hidrogênio para PaCOS

Síntese e caracterização de perovskitas do tipo LaNi1-xCu xO3 para a purificação de hidrogênio para PaCOS

Summary Report on Solid-oxide Electrolysis Cell Testing and Development

Near-ambient X-ray photoemission spectroscopy and kinetic approach to the mechanism of carbon monoxide oxidation over lanthanum substituted cobaltites

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