Potential of an Alumina-Supported Ni3Fe Catalyst in the Methanation of CO2: Impact of Alloy Formation on Activity and Stability

Abstract

A promising bimetallic 17 wt % Ni3Fe catalyst supported on γ-Al2O3 was prepared via homogeneous deposition–precipitation for the application in the methanation of CO2 to gather more detailed insight into the structure and performance of the catalyst compared to state-of-the-art methanation systems. X-ray diffraction (XRD) analysis, detailed investigations using scanning transmission electron microscopy (STEM) combined with energy dispersive X-ray spectroscopy analysis (EDX) of single particles as well as larger areas, high-resolution transmission electron microscopy (HRTEM) imaging, temperature-programmed reduction (H2-TPR), and in-depth interpretation of Raman bands led to the conclusion that a high fraction of the Ni and Fe formed the desired Ni3Fe alloy resulting in small and well-defined nanoparticles with 4 nm in size and a dispersion of 24%. For comparison, a monometallic catalyst with similar dispersion using the same preparation method and analysis was prepared. Using a fixed-bed reactor, the Ni3F...