Hierarchical Fe-modified MgAl2O4 as Ni-catalyst support for methane dry reforming

MgAl(2)O(4)and its Fe-modified analogue (MgFexAl2-xO4) were synthesized as supports with a nanostructure by a hydrothermal process, and employed as supports for Ni catalysts in methane dry reforming (DRM). All prepared supports had a hierarchical architecture displaying clusters of nanosheets. Fe-modified MgAl(2)O(4)was characterized by X-ray diffraction (XRD), N(2)adsorption-desorption, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and temperature-programmed desorption (TPD). The activity and stability of the catalysts with a hierarchical support were tested in DRM at 750 degrees C, 111.3 kPa, and a CH4 : CO(2)ratio of 1. The Ni/MgAl(2)O(4)sample with a 0.5 Mg : Al molar ratio showed higher activity than Ni on common MgAl(2)O(4)due to the larger surface area and stronger metal interaction with the hierarchical support. Besides, a series of Ni/MgFe(x)Al(2-x)O(4)catalysts with an Fe/Ni ratio between 0 and 0.5 was synthesized and reduced, yielding a supported Ni-Fe alloy. The structure evolution of the Ni/MgFe(x)Al(2-x)O(4)catalyst during H(2)temperature-programmed reduction (H-2-TPR), CO(2)temperature-programmed oxidation (CO2-TPO), and dry reforming was investigated byin situXRD. For Fe/Ni <= 0.05, a Ni-Fe surface alloy is obtained with high catalyst activity, efficient control of carbon deposition and superior regeneration ability. Ni supported on hierarchical Fe-modified MgAl(2)O(4)proves to be a promising and effective catalyst for methane dry reforming