3D Imaging and Structural Analysis of a Mesoporous-Silica-Body-Supported Eggshell Cobalt Catalyst for Fischer-Tropsch Synthesis

For understanding the relationship between the structure and catalytic property and further optimizing the synthetic steps, it is imperative to obtain basic information about the characteristics of heterogeneous catalysts, such as porosity, dispersion, and accessibility of the active metal phases. Herein, we reported a multiscale analysis of an eggshell-Co-based catalyst for the Fischer-Tropsch synthesis (FTS), which was prepared by wetness impregnation. Conventional characterization techniques, such as mercury porosimetry, nitrogen physisorption, and transmission electron microscopy (TEM), were employed for obtaining basic information about the porosity and dispersion of cobalt on the nanoscale; in addition, phase-contrast Xray computed microtomography (X-ray mCT) as a powerful method was employed for obtaining vitally complementary information regarding the 3D structure of a millimeter-sized mesoporous silica support and a full-field view of the macroscopic distribution of cobalt. The Co reduction behavior and FTS performance was correlated with the structure analyses, highlighting the importance of simultaneously controlling the dispersion and spatial distribution of Co ranging from macro to nanoscale.