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 Co3O4, CoO and Co powders were used as reference materials.