Effects of cerium oxide on the activity of Fe-Ni/Al2O3 catalyst in the decomposition of methane

Abstract

The Fe-Ni/γ-Al2O3 catalyst promoted with cerium oxide was investigated in the decomposition of methane. Using X-ray diffraction analysis (XRD) and temperature-programmed reduction analysis (TPR-H2), it was established that the introduction of cerium oxide into composition of Fe-Ni/γ-Al2O3 promotes the formation of Ni-Fe alloys, because as well as an increase in the mobility and amount of active oxygen of the Fe-Ni/Al2O3 catalyst with the introduction of cerium. The results also showed that the addition of cerium oxide to Fe-Ni/γ-Al2O3 improved the catalytic stability by increasing the carbon diffusion rate and preventing the formation of encapsulated carbon. Analysis of spent catalysts using scanning (SEM), transmission electron microscopy (TEM), and Raman spectroscopy showed that carbon in the form of graphene is formed on Fe-Ni/γ-Al2O3, the introduction of cerium oxide contributes to the dispersion of the active phases of the Fe-Ni/γ-Al2O3 catalyst, thereby creating conditions for the nucleation and growth of free carbon in the form of nanotubes.