Ni-Fe Catalysts Supported on Nano-Al2O3 for Reverse Water Gas Shift Reaction

چکیده مقاله

10Ni, 7Ni-3Fe, 3Ni-7Fe and 10Fe cataysts were supported on nanocrystalline Al2O3 and evaluated in reverse water gas shift reaction. Al2O3 was prepared by precipitation and Ni-Fe catalysts were prepared by impregnation technique. The prepared samples were charactrized by X-ray diffraction (XRD), N2 adsorption-desorption (BET), and scanning electron microscopy (SEM) techniques. The BET surface area of prepared γ-alumina support is 126.81 m2.g-1. The γ-alumina support shows pore sizes distribution of about 1-4 nm. Among the prepared Ni-Fe/Al2O3 catalysts, 3Ni-7Fe catalyst showed high CO2 conversion of 39.5 % at 600 oC and its CO selectivity was higher than 90% at all temperatures. 10 Fe showed lowest CO2 conversion especially at temperatures lower than 400 oC, but its CO selectivity was higher than 99 % at all temperatures. 10Ni and 7Ni-3Fe showed good CO2 conversions but had low CO selectivity among the prepared samples. Addition of Fe to Ni increasind the monodispersity of nickel species and suppressed the methanation reaction.