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.