Industrial & Engineering Chemistry Research | 2019
High-Temperature Fischer–Tropsch Synthesis of Light Olefins over Nano-Fe3O4@MnO2 Core–Shell Catalysts
Abstract
A one-pot hydrothermal process was adopted to synthesize nano-Fe3O4@MnO2 core–shell catalysts with diverse thicknesses of MnO2 for the high-temperature Fischer–Tropsch (HTFT) synthesis of light olefins. Herein, the effects of the Mn amount on the morphology and catalytic performance of the catalysts were evaluated by Ar adsorption–desorption, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), H2 temperature-programmed desorption (H2-TPD), CO temperature-programmed desorption (CO-TPD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) equipped with energy-dispersive spectroscopy (EDS)-lining, aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) combined with EDS-mapping, and Mossbauer spectroscopy. Both EDS-lining and EDS-mapping had verified the core–shell structure in the fresh samples. The core–shell structure benefited the reduction of Fe3O4, electr...