On the structural, textural and morphological features of Fe-based catalysts supported on polystyrene mesoporous carbon for Fischer–Tropsch synthesis

Abstract

The aim of this work was to produce two iron-based catalysts supported on polymeric mesoporous carbon (PMC) support, analyze them and evaluate their use in Fischer–Tropsch synthesis (FTS). Two PMC supports differing only in synthesis steps were evaluated. The Fe-PMC catalysts were prepared by wet impregnation method and were characterized, before activation, by X-ray diffraction (XRD), X-ray fluorescence analysis (XRF), X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption, temperature-programmed reduction (TPR), Mössbauer spectroscopy, Raman spectroscopy and scanning electron microscopy coupled to X-ray energy dispersion spectroscopy (SEM-EDS). Fischer–Tropsch synthesis was carried out to evaluate the activity of the catalysts. The synthesis was carried out in a slurry reactor operating at 513–543K, 20–30atm, and 1:1 CO:H2 molar ratio. X-ray diffraction showed that the calcined iron catalyst did not modify the structure of PMC and that Fe was present in the form of iron carbides, α-Fe2O3 and Fe3O4. The addition of iron in the supports lowered the specific surface area of the support. Fischer–Tropsch synthesis activity and C5+ hydrocarbon selectivity increased as oxygen groups were incorporated into the support. The Fe-PMC catalysts displayed moderate conversion (40%) and high selectivity towards the production of C5+ (72%, w/w).