ToF-SIMS as a versatile tool to study the surface properties of silica supported cobalt catalyst for Fischer-Tropsch synthesis

The aim of this work was to determine the surface properties of silica supported cobalt catalyst for Fischer-Tropsch synthesis. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used for this purpose as a main analytical tool. Moreover, X-ray diffraction (XRD), temperature programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis/differential thermal analysis/mass spectrometry (TG-DTA-MS) and BET surface area measurements were performed. The influence of a preparation method and treatment conditions on the surface composition (including the formation of different phases of cobalt oxides, cobalt silicate and decomposition of cobalt nitrate - catalyst precursor), cobalt oxidation degree and metal dispersion was studied. 10%Co/SiO₂ catalysts prepared by impregnation and deposition-precipitation methods were investigated. Moreover, pure Co ₃O₄, CoO and Co powders were used as reference materials.