Facile Route for Synthesizing Ordered Mesoporous Ni–Ce–Al Oxide Materials and Their Catalytic Performance for Methane Dry Reforming to Hydrogen and Syngas

Abstract

A series of ordered mesoporous Ni–Ce–Al composite oxides with various cerium contents were synthesized via a one-pot route: evaporation-induced self-assembly (EISA) strategy and tested in methane dry reforming for hydrogen and synthesis gas production. Using this method, the hydrophobic nickel precursor was directly incorporated into the hydrophobic cores of surfactant micelles, and thus, the highly dispersed Ni nanoparticles were stabilized inside the mesopore channels of an alumina matrix. For comparison, Ni-based catalysts were also prepared by a traditional impregnation method. The characterization results confirmed that the ordered mesostructures were well maintained in all of the cerium-incorporated Ni–Al materials (Ce/(Ce + Al) molar ratio ≤ 3%). The catalyst with a Ce/(Ce + Al) ratio of 1% exhibited the highest catalytic activity (with CO2 and CH4 initial conversions being 70% and 68% at 700 °C, respectively) and remained stable in a methane dry reforming reaction. This improved activity can be attributed to the large surface area and high dispersion and reducibility of Ni nanoparticles, which were stable because of the stable alumina framework and high oxygen mobility in these cerium-containing samples. Resistance to carbon deposition was found over the Ni–Ce–Al catalyst, whereas amounts of graphitic carbon species were found over the Ni-impregnated catalysts, which was responsible for deactivation.

Ordered mesoporous “one-pot” synthesized Ni-Mg(Ca)-Al2O3 as effective and remarkably stable catalysts for combined steam and dry reforming of methane (CSDRM)

“…Comparable stability effects were recently claimed in the case of "one-pot" synthesized oxide-based catalysts tested in DRM [43,45,51,52,61] or in SRM [46], but such types of materials were never considered yet in the combined CSDRM reaction that involves much more drastic conditions (especially steam and high temperatures). Moreover, the present method introducing the active phase (Ni) and the structuring agent (P123 Pluronic triblock copolymer) in a same synthesis batch was, to our knowledge, never considered regarding nickel-alumina based mesoporous catalysts.…”

Efficient hydrogen production from ethanol steam reforming over La-modified ordered mesoporous Ni-based catalysts

“…The patterns for all the shown meso-xLaNiAl samples exhibit mainly two wide diffraction peaks, which are corresponding to amorphous Al 2 O 3 [29]. No peaks associated with nickel species are found, indicating the high dispersion of Ni species inside the framework of the materials due to the advantages of the one-pot method [54]. Moreover, no La 2 O 3 characteristic peaks are observed for meso-xLaNiAl catalysts, indicating lanthanum species are either amorphous or well dispersed.…”

Effect of support composition on the origin and reactivity of carbon formed during dry reforming of methane over 5wt% Ni/Ce1−xMxO2−δ (M=Zr4+, Pr3+) catalysts

“…Bobin et al [41] have shown that the amount of the active carbon pool which participates in dry reforming over supported Ni and Ni-Ru was very small. Dry reforming of methane over Ce 1−x−y M 1 x M 2 y O 2 -supported Ni catalysts (M 1 and M 2 are rare earth metals) with supports possessing high OSC (mol O g −1 ) was reported [10,[14][15][16][17]42,43]. The high activity of these catalytic systems was related with the participation of support's oxygen vacancies towards dissociation of CO 2 .…”