MgO/NiAl2O4 as a new formulation of reforming catalysts: Tuning the surface properties for the enhanced partial oxidation of methane

Magnesia modified nickel aluminate spinel catalysts were synthesised and characterised by BET, TEM, XRD, H2-TPR, XPS, CO2-TPD and TGA-MS techniques. The addition of this promoter induced significant changes in the textural, structural and chemical properties of the resulting spinel derived catalysts...

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Detalles Bibliográficos
Autores: Boukha, Zouhair, Jiménez González, Cristina, Gil Calvo, Miryam, De Rivas Martín, Beatriz, González Velasco, Juan Ramón, Gutiérrez Ortiz, José Ignacio, López Fonseca, Rubén
Tipo de recurso: artículo
Fecha de publicación:2016
País:España
Institución:Universidad del País Vasco
Repositorio:Addi. Archivo Digital para la Docencia y la Investigación
OAI Identifier:oai:addi.ehu.eus:10810/71099
Acceso en línea:http://hdl.handle.net/10810/71099
Access Level:acceso abierto
Palabra clave:nickel aluminate
magnesium oxide
surface basicity
partial oxidation of methane
Descripción
Sumario:Magnesia modified nickel aluminate spinel catalysts were synthesised and characterised by BET, TEM, XRD, H2-TPR, XPS, CO2-TPD and TGA-MS techniques. The addition of this promoter induced significant changes in the textural, structural and chemical properties of the resulting spinel derived catalysts. Thus, it enhanced the resistance of the deposited Ni particles against sintering, whereas, upon increasing MgO loading, it drastically modified the density and the strength of the surface basic sites. In fact, an apparent weakening of the surface basic sites with the abundance of highly dispersed Mg species was interestingly observed. The changes provoked by MgO addition deeply influenced the catalytic performance of the prepared samples in the partial oxidation of methane reaction at 700 °C. In this sense, it was found a good correlation between the measured density of the strong basic sites on the different samples, including the bare NiAl2O4, and their catalytic activity. Hence, the MgO(5 wt.%)/NiAl2O4 sample, with a magnesium loading close to the theoretical monolayer and the lowest strong basic density sites, exhibited the best catalytic performance under both stoichiometric (O/C = 1) and non-stoichiometric (O/C = 0.75) conditions during a relatively prolonged time on stream.