Fischer–Tropsch Synthesis with Fe/Cu/La/SiO<SUB>2</SUB> Nano-Structured Catalyst

Abstract

Nano-structure Fe2O3, CuO and La2O3 components were prepared by micro-emulsion method and then Fe/Cu/La/SiO2 nano-structure catalyst was prepared by mixing and re-slurring the mixture by tetraethylorthosilicate (TEOS). The catalyst composition was designated in term of the atomic ration as: 100Fe/5.64Cu/0.1La/19Si. Structural characterization of nano-structured Fe2O3, CuO and La2O3 components was performed by Transmission Electron Microscopy (TEM), powder X-ray diffraction, Temperature Programmed Reduction (TPR) techniques. Particle size for obtained components was about 20, 21.6 and 12.6 nm for Fe2O3, CuO and La2O3 respectively determined by using XRD pattern (Scherrer equation) and TEM images. Catalytic activity and product selectivity were conducted in a fixed-bed stainless steel reactor and compared with conventional iron catalyst. The results reveal that reducing particle size of catalyst increased the catalyst performance. Also, olefin/paraffin ratios decreased in comparison with conventional catalyst.

Catalytic activity of Fe/ZrO2 nanoparticles for dimethyl sulfide oxidation

“…The study of Iron oxides nanoparticles has attracted intensive attention over the past decades due to the potential applications in catalysis [18,19]. Recent studies showed nanosized iron particles are widely appearing to be economically feasible on an industrial scale for Fischer-Tropsch process [20][21][22]. In other report immobilized Iron (III)-substituted polyoxotungstates is found effective catalysts for solvent-free aerobic oxidation of n-hexadecane [23].…”

Size dependence on reduction kinetic of iron based Fischer–Tropsch catalyst

“…The precursors of the nano structure catalysts were prepared by coprecipitation in a water-in-oil microemulsion as described previously [11][12][13][14][15][16][17]. Similarly Fe/Cu/La catalyst precursors in microemulsion system were precipitated in the same semi-batch reactor.…”

“…Since the catalytic properties of the nanoparticles depend on the size, nanoparticles with different sizes are expected to have different catalytic activity and selectivity. The dynamic surface of nanoparticles also depends on the size: smaller nanoparticles have higher surface energy and thus more prone to surface reconstruction, which can lead to different catalytic dynamics for nanoparticles with different sizes [11][12][13][14][15][16][17][29][30][31][32].…”

“…Eq. (11) predicts that the reduction rate constant will increase, if particle size decreases. This fact is observed for the reduction of hematite in iron catalyst at present work.…”

“…Recent studies showed that nano-sized iron particles play an essential role to achieve high Fischer-Tropsch synthesis (FTS) activity [8][9][10][11][12][13][14][15][16][17]. Iron-based catalysts have been preferred for synthesis gas derived from coal or biomass because of the excellent activity toward water-gas-shift reaction; therefore, its utilizes synthesis gas with a low H 2 /CO ratio directly without an upstream shift-step [18][19][20][21][22][23][24].…”