(41b) Carbon Nanotube-Supported Catalysts Prepared By a Modified Photo-Fenton Process for Fischer-Tropsch Synthesis

We demonstrate use of a facile, scalable,
modified photo-Fenton process for the preparation of carbon nanotube
(CNT)-supported Fischer-Tropsch catalysts. Use of a
green catalyst precursor and an oxidant in photo-Fenton process enhances the
formation of small and well-dispersed catalyst particles on CNTs. Catalysts prepared by photo-Fenton process do
not require a calcination step due to the absence of foreign components
(nitrate, chloride, and acetate) that have to be removed during post-synthesis
treatment. The synthesized catalysts were characterized by X-ray diffraction
(XRD), BET, hydrogen temperature-programmed reduction (H₂-TPR), Raman spectroscopy, transmission
electron microscopy (TEM), and inductively coupled plasma (ICP). H₂-TPR
results show a high dispersion percentage and smaller catalyst particles
with narrow particle size distributions. The performance of catalysts (CO conversion, C5+ selectivity, and
catalyst lifetime) prepared by photo-Fenton process was evaluated during FTS
and compared to CNT- and SiO₂-supported catalysts synthesized via conventional
method (incipient wetness impregnation). In general, CNT-based catalysts
prepared by photo-Fenton process (Co or Fe) show a higher performance at lower
reaction temperature (200˚C for Co and 250˚C for Fe) in comparison to
conventional catalysts. In particular, Co catalysts obtained from photo-Fenton process
show outstanding selectivity for liquid hydrocarbons (C5+) ~ 70% and CO
conversion ~80%.