No abstract

Ordered mesoporous tricompound NiO−CaO−Al 2 O 3 composite oxides with various Ca content were first designed and facilely synthesized via a one-pot, evaporation-induced, self-assembly (EISA) strategy. The obtained mesoporous materials with advantageous textural properties and superior thermal stabilities were investigated as the catalysts for the carbon dioxide reforming of methane reaction. These mesoporous catalysts entirely showed high catalytic activities as well as long catalytic stabilities toward this reaction. The improved catalytic activities were suggested to be closely associated with the advantageous structural properties, such as large specific surface areas; big pore volumes; and uniform pore sizes, which could provide sufficient "accessible" active centers for the gaseous reactants. In addition, the "confinement effect" of the mesoporous matrixes contributed to stabilizing the Ni active sites during the processes of reduction and reaction, accounting for the long lifetime stabilities of these mesoporous catalysts. The modification of Ca played dual roles in promoting the catalytic activities and suppressing the carbon deposition by enhancing the chemisorption of the CO 2 . Generally, the ordered mesoporous NiO−CaO−Al 2 O 3 composite oxides could be considered as promising catalysts for the carbon dioxide reforming of methane reaction.

Ordered mesoporous NiO-Al 2 O 3 composite oxides with different nickel content were facilely synthesized via an improved evaporation induced self-assembly (EISA) strategy with Pluronic P123 as template in absolute ethanol solvent. The catalytic properties of the obtained mesoporous materials were investigated for the carbon dioxide reforming of methane reaction. These materials were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), N 2 adsorption and desorption characterization, H 2 temperature-programmed reduction (TPR), and thermogravimetry (TG). It was observed that these catalysts with mesostructure presented both high catalytic activity and long stability. The improved catalytic performance was suggested to be closely associated with both the amount of ''accessible'' active centers for the reactants on the mesopore wall surface and the stabilisation of the active sites by the alumina matrix due to the ''confinement effect'' of the mesopores. The ''confinement effect'' existing among the mesoporous structure of the materials contributed to preventing Ni particles from sintering under severe reduction and reaction conditions. The stabilized Ni nanoparticles had strong resistance to carbon deposition, accounting for no deactivation after a 100 h long-term stability test at 700 1C. Thus, the ordered mesoporous NiO-Al 2 O 3 composite oxides promised a novel and stable series of catalyst candidates for the carbon dioxide reforming of methane reaction.

No abstract

No abstract

No abstract

No abstract

No abstract