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Artigos publicados

Os pesquisadores do Instituto Nacional de Tecnologia publicam artigos técnico-científicos em revistas nacionais e internacionais.

As informações disponibilizadas nesta seção estão datadas a partir de 2016.

Para ver a listagem completa das produções científicas acesse o Repositório Institucional do INT.

2016

TÍTULO: Influence of carbide formation on oxygenates selectivity during Fischer-Tropsch synthesis over Ce-containing Co catalysts

REVISTA: Catalysis Today, v.261, p.40-47, 2016.

AUTORES: NORONHA, Fábio Bellot; SHAFER, Wilson D.; DAVIS, Burtron H.

ANO DE PUBLICAÇÃO: 2016

RESUMO: Fischer-Tropsch (FT) synthesis was performed over 15%Co/CeSi and 15Co/CeMnSi catalysts using a 1 L CSTR at 230ºC, 1.89 MPa and a H2/CO ratio of 1.86. The oxygenate selectivity for both catalysts increased with increasing time-on-stream during FT synthesis. X-ray diffraction, EXAFS and HR-TEM analyses of fresh catalysts and those withdrawn during FT synthesis indicate that increases in the selectivity for oxygenates with time are related to structural changes in the catalyst, most likely associated with a transition from a metallic cobalt surface to one containing surface cobalt carbide. Moreover, a significant effect of carburization on increasing the selectivity for oxygenates was observed for FTS using the 15Co/CeMnSi catalyst. The reactivity of CO was inhibited by the presence of carbon on the surface of cobalt which promoted oxygenate formation through a CO insertion mechanism.

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TÍTULO: Ethanol conversion at low temperature over CeO2-supported Ni-based catalysts: effect of Pt addition to Ni catalyst

REVISTA: Applied Catalysis B: Environmental, v.181, p.754-68, 2016.

AUTORES: NORONHA, Fábio Bellot; MORAES, Tamara Siqueira; RABELO NETO, Raimundo Crisostomo

ANO DE PUBLICAÇÃO: 2016

RESUMO: The effect of Pt addition on the performance of Ni/Ce02 catalyst for the low temperature steam reforming of ethanol is investigated. The reaction mechanism was explored using diffuse reflectance infrared spectroscopy under reaction conditions and temperature-programmed surface reaction of ethanol. The addition of Pt to Ni/Ce02catalyst promoted the decomposition of dehydrogenated and acetate species to hydrogen, methane, CO and carbonate species. Furthermore, the presence of Pt reduced the rate of catalyst deactivation. In situ X-ray absorption studies revealed the formation of a nickel carbide phase during steam reforming of ethanol over Ni/Ce02 catalyst, which was associated with amorphous carbon deposition and catalyst deactivation. X-ray photoelectron spectroscopy in combination with kinetic and structural data was consistent with a partial Pt monolayer on Ni in the bimetallic catalyst. The segregation of Pt on the surface of the Ni particles minimized the formation of nickel carbide and promoted catalyst stability.

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