Facile one-step synthesis of mesoporous Ni-Mg-Al catalyst for syngas production using coupled methane reforming process

摘要

Mesoporous Ni-Mg-Al and Ni-Al catalysts were facilely synthesized via evaporation-induced self-assembly (EISA) method and employed for coupled reforming reaction consisting of dry reforming of methane (DRM) and partial oxidation of methane (POM) to produce syngas (H-2 + CO). The Ni-Mg-Al and Ni-Al catalysts with encapsulated nickel nanoparticles were directly synthesized in one-pot way. For comparison, Ni/Al2O3 as reference catalyst was also prepared by general impregnation method. Characterization by BET, XRD and H-2-chemisorption revealed that the Ni-Mg-Al catalyst owned larger surface area and higher Ni dispersion as well as smaller metallic Ni particles size compared to Ni-Al and Ni/Al2O3 catalysts. CO2-TPD demonstrated that the Ni-Mg-Al catalyst presented stronger basicity due to Mg incorporation. H-2-TPR confirmed that the reduction of Ni-based species to Ni-0 was performed in high temperature due to the formed NiAl2O4 phase. Activity tests indicated that this Ni-Mg-Al catalyst, due to its excellent physicochemical property, exhibited higher CH4 conversion, H-2 selectivity, and H-2/CO ratio in the coupled DRM-POM reaction. XRD, SEM and TG-DTA analyses of the used catalysts disclosed that the Mg-modified Ni-Mg-Al catalyst for syngas production using coupled DRM-POM reaction exhibited robust resistance to coke deposition. Consequently, by the synergistic cooperation between the coupled DRM-POM reaction and Mg-modified Ni-Mg-Al catalyst, high catalytic activity and stability could be accomplished to produce syngas.