SYNTHESIS, CHARACTERIZATION AND PERFORMANCE OF CNTsSUPPORTED BIMETALLIC NANOCATALYSTS IN FISCHER-TROPSCH REACTION

Fischer-Tropsch Synthesis (FTS) is a very important process which deals with the
chemical conversion of synthesis gas into hydrocarbons and oxygenates with a broad
range of chain lengths and functionalities. FTS has a potential to produce liquids fuels
and chemicals from a variety of chemical feedstocks such as natural gas, coal and
biomass. Industrially alumina (Ab03) and silica (Si02) supported cobalt (Co) based
are extensively used. There are some problems associated Co-based catalysts
supported on conventional metal oxides such as metal-support mixed oxide formation,
sintering. lower reducibilties and dispersion.
The objective of this project was to synthesize. characterize and evaluate the
performance of CNTs-supported bimetallic nanocatalysts in a Fischer-Tropsch
Synthesis (FTS). The bimetallic nanocatalyst systems consisted of Co-Fe, Co-Mn and
Co-Mo. A total metal loading of 5 weight % and various formulations (Co/CNTs,
70Co30M/CNTs, 50Co50M/CNTs. 30Co70M/CNTs and M/CNTs) have been
synthesized using a wet impregnation method on CNTs support. The effects of
promoters such as potassium (K), niobium (Nb), copper (Cu) and platinum (Pt) at
various levels, on the physicochemical properties of the nanocatalysts have been
investigated. The physicochemical properties of the nanocatalysts were investigated
using N2 physical adsorption, field-emission scanning electron microscopy (FESEM),
transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS),
X-ray diffraction (XRD), CO-chemisorption, hydrogen temperature-programmed
desorption (H2-TPD), temperature-programmed oxidation (TPO), carbon dioxide
temperature-programmed desorption (COr TPD) and hydrogen temperature�programmed reduction (H2-TPR). The performance of all the synthesized catalysts in
FTS was investigated in a fixed-bed microreactor at atmospheric pressure and various
feed ratios of the reactants (H2/CO). temperature, and space velocity while selected
nanocatalysts were investigated at 20 bar.